A/N: While I normally don't see much of a difference between reading stories on FFN or elsewhere, in this case this fic does have some special formatting, starting in chapter 4, that FFN simply won't allow. I've approximated it with the limited formatting that is allowed, but if you'd like to read it in its original form, I'd advise you instead read it on the AO3. There's a link in my profile.

Aside from Marvel, this story also borrows extremely heavily from Journey to the West.


The first indication that the mission was going to go FUBAR had actually been back on the Helicarrier, when the SHIELD technician had said, "Now, when you fire it on wide-beam, it tends to vibrate too strongly for most people to hang onto, but someone with superhuman strength – uh, such as yourself – should have no problem. You just need to have a firm grip," while in the background, Clint doubled over laughing.

The second indication had been when the technician, and the technician's superior, and his superior, had all agreed that a test-firing was out of the question, because, "Well, in previous tests after it's fired once it tends to need some maintenance before it's good to go again," which had made Clint – nearly recovered – lose it all over again.

So the fact that Steve was currently fucked, and not in any of the ways that had set Clint off laughing, was not actually a surprise – but when he had a super-zombie about point-one second away from ripping his head off, that was not any sort of consolation.

The guy – who looked like he was in his fifties, getting on in years – came at him in a near-blur as Steve dived out of the way, slipping on the ice coating the ground. Fortunately for his skull, the super-zombie also slipped. The entire hillside in every direction northward (and somewhat southward) resembled an oddly sculpted ice-rink: though the vibrations had made it damn near impossible to aim the unimaginatively named 'Ice Ray-Gun' on wide-beam (the ray-gun itself had vibrated to pieces a second ago) enough to catch the super-zombie, the visible effects that it had had were nonetheless pretty... chilling.

"Abort, abort!" Steve yelled into his comm. as he took off running; as soon as the super-zombie regained his footing he'd be about and catching up faster than Steve could hope to run, but every second of distance bought counted. "Target is live and hot, I need backup – "

Backup, these days, meant the Hulk.

Steve tried not to feel too resentful of Thor about that. Or of Tony. Right now, though, there was no time to think about it at all; he was already pivoting, skidding on the ice as he did so, instinct telling him that the attack was coming – now.

Flames hit the shield, melting the ice around him as he went to one knee, ducking to hide entirely behind it. The next moment he launched himself forward and up, and slammed shield-first into something heading towards him with a velocity about equal to that of a bullet train. The shield, mighty equalizer that it was, brought them both to a standstill, and while the super-zombie was still processing that fact Steve got his footing in the muddy hillside and heaved, launching the zombie upward and back down the hill. Thank the Lord that at least they couldn't fly – Steve dove out of the way of another blast of fire and jogged backward.

The zombie spit against the ground, acid-green spit that made the mud bubble, and growled with two distinct voices, "You defy us? We will consume you."

"Mister, better than you have tried," Steve snapped back, but his heart wasn't in it.

At the end of the day, this guy wasn't his enemy. He was just another victim.

The zombie rushed forward.

The first time Steve had gone up against a super-zombie, he'd gotten his ass handed to him; but then he'd been weak from hunger and nearly becoming a zombie himself. He was still nowhere near fast enough to keep up to this zombie, but he had the shield on guard, and it took the full force of the first few blows – as though the zombie couldn't believe that it could withstand the hits. That was fine by Steve; it was when the zombie gave up trying to hit it and started grabbing at it, instead, to try to pull it away, that he was going to get into trouble – and it didn't take longer than five clumsy but super-strength punches. Steve twisted under and to the side, kicking out the creature's knee long enough to get it down, get it off him, so he could back-off and resume guard. It had no real sense of how to fight – just pure brute strength, speed, and – he ducked behind his shield again – the ability to breathe fire. And spit acid.

But that didn't mean it couldn't learn. The knee slid back into place almost immediately, crackling like a log in a stove, and the zombie lunged. Steve brought the shield down, but wasn't fast enough compared to the extremis-enhanced speed. Instead of blocking he only managed to slice into the creature's arm, but that healed immediately, around the shield. He pushed to the side, the zombie grabbed the top edge with its other hand, and Steve's much better leverage and positioning lost to alien-and-Stark-built nanotechnology: the shield went flying, and a moment later Steve went flying too, all the wind knocked out of him by a blow that would have pulverized any other guy – one without the serum, and without the best body armour SHIELD could put out.

He was plucked out of mid-air at a punishing speed, the roar hitting him only a moment before the iron grip of the War Machine dragged him up,up. Below them, the super-zombie screeched and leapt – but although it could equal their height, it had no real manoeuvrability in the air, and Rhodey evaded easily.

"My shield," Steve gasped, the moment he could breathe. They were far up, now, hiding in the low clouds.

"We'll get it when Hulk's done with him," Rhodey replied shortly.

Steve couldn't argue with that. Didn't mean he couldn't argue with Rhodey, though. "What're you doing out here?" His voice was breathy; the height was making it harder than it ought to have been to get his wind back. Or maybe the zombie had hit him harder than he'd thought. "You're supposed to be in Asia." The western edge of it, sure, but that was still far enough that Rhodey had to have been on his way before Steve had even left the Helicarrier.

"Yeah, well, a half-hour ago I heard my team lead had gone all suicidal," Rhodey bit back, his voice colder than the frigid clouds surrounding them.

Son of a – "You heard wrong." He made his voice flat – flat, and nothing more. Rhodey was wrong, but if he'd gotten this idea into his head – damn it. He'd thought Rhodey trusted him. They worked well together.

"Really, man?" Rhodey demanded. "Banner was three minutes out when you put out that mayday – you lasted less than a minute. You wanna tell me what the hell – "

"You grabbed me after less than a minute," Steve snapped, and then barely bit down on a snarl of frustration – against himself. Arguing about this was worse than useless. "I know what I'm – "

"I'm not having this conversation with you while we're a couple thousand feet up and you can't fly, Captain," Rhodey interrupted.

Steve stamped on the urge to growl, 'Retired.' Even the people at SHIELD who thought he was crazy still called him Captain.

And that was pretty much everybody.

"You were told it couldn't be used continuously," Dr. Martell said, her voice hitting a tone of complaint just short of whining. "Three short bursts –two, ideally!"

"It was vibrating all over the place," Steve said evenly. "Even Hawkeye couldn't have hit that thing with it." He tried not to feel too much irritation at Martell – like everyone else in her division, she'd been working long, exhausting hours for the past three months, and it showed in every line on her face, in the long bags under her eyes.

"The moisture content of the air..." suggested Dr. Belgrade.

"We worked that problem out."

"But with the pressure changes from transport – "

Fury cut off the scientists before they could really get into the argument. "Gentlemen. Ladies. I expect you'll want to continue work on the prototypes – immediately. I don't have to remind you of the time limits we're facing."

"Sir," Martell said, shoving her chair back and leaving. The others quickly followed suit, leaving Steve the only one sitting at the table – Fury never seemed to actually sit down anywhere.

"You're sure Agent Barton couldn't have managed that shot?" Fury asked after a moment.

"Positive, sir." And not just because Clint would need a mount to handle it; the gun weighed a good three hundred pounds. Otherwise, the mission would have been Clint's, for all that it was really less a 'gun' and more a directed bomb. If Engineering hadn't been split sixty-forty on whether they'd be able to integrate it with the War Machine without compromising the suit, Rhodey would have been SHIELD's second choice for today's test-run.

The freeze-bomb wasn't a final solution – that, SHIELD was still working on, although it seemed more hopeless with every day that went by with no further progress on tracking down Borjigin and Hansen. Both Steve and Rhodey had retrieved extremis samples from across Asia, but so far the stuff adapted to whatever 'anti-virus' code the techs cooked up to throw at it, and twice it had become so much more lethal in the process that they'd nearly lost containment.

A month ago, they had lost containment, and a good thirty-three people with it. Since then, progress on that front had slowed to a crawl.

Shapanka's wrist-blaster freeze-ray was only good if they could actually nail the zombies with it: easy enough when it came to the regular ones, but extremis gave the enhanced such good reflexes that they could see the beam coming at them and avoid it easily. Larger setups, though, increased massively in size and decreased massively in portability, making them worthless at hunting down fast-moving, tiny targets; today's test-run had been the first real 'portable' prototype that had even had a chance at working. Conventional weaponry was next to useless against them: unless it was a direct hit (and even sometimes if it was) they healed immediately, and they could dodge almost anything, unless they had a reason to stick around. A target.

Hence, the Hulk. But the Hulk, though he'd given it a few good shots, couldn't smash all of them, and was becoming more and more reluctant to smash any of them. Slowly, but surely, the idea that these people were innocent, that they'd been taken over by something else, had worked its way into Hulk's brain. And he didn't like it any more than the rest of them did.

Fury stared at Steve a moment longer, like he was contemplating something – or maybe he was just trying to make Steve squirm. It wasn't, Steve thought morosely, something he needed encouragement to do, not when he knew that Bruce was in for another night of sedation, lest he Hulk out from screaming nightmares about squishing heads in his fists. It was Clint's turn on Hulk-watch tonight, fortunately, though if Steve didn't think he'd only be a reminder of the day's work, he'd have ensconced himself in the chair outside Bruce's room anyway.

Finally, Fury nodded. "Dismissed."

"Sir."

Outside in the hallways, agents let their eyes slide past him; Steve ignored them and tried not to feel too alone. His team had other assignments – Rhodey hadn't even fully landed on the Helicarrier, just dropped Steve to the deck and then taken off; Natasha was still in France; and Clint was spotting for Bruce, or rather, the Hulk. He couldn't begrudge any of them for not being there, especially not when Fury's only comment about Rhodey's intervention had been a mild, "He made good time," and an assurance that retroactive orders were being issued to cover any appearance of disobedience.

Fury was willing to believe Steve's whole story about alternate worlds and dimensions, even though he knew that Steve wasn't telling him everything. Steve wasn't sure what he'd done to earn that trust, but if even Fury thought that Steve had been an idiot in planning this mission...

You should talk to your shrink, Rogers, he told himself. It sounded like a mix of Fury and Tony in his head.

He should not punch the wall, so he made himself relax his fists, and then he headed for the hanger and the chance that someone might be flying back to New York in the next few hours.

The drab brown walls of his apartment were a dismal 'welcome back'. Two months, and he still hadn't gotten around to putting up any pictures or paintings. But every time he thought about it, there was the niggling feeling that if he started trying to make the apartment feel like home, it actually would become home – permanently.

A month ago Tony's – the other Tony's – remains had disappeared from his coffin, which had gotten Dr. Foster excited, although when Tony failed to show up in his place everyone else had stopped caring. Two and a half months ago, Tony had sworn he'd be right behind Steve.Something had happened – but Tony would find a way. Or Anthony would finally show up, and solve everything with a snap of his fingers. Or maybe SHIELD would move portal research off the backburner. Something.

When he didn't want to dwell on the reasons why these might become his long-term accommodations, Steve told himself it didn't matter because he spent so little time here anyway. Half the nights he bunked with Bruce; most of the days he spent training on the Helicarrier or on solo missions into zombiefied territory, scouting and gathering samples that others couldn't, not with any relative degree of safety. Really, this place was just a spot to crash and sleep occasionally. For all that it was located in Brooklyn, it would never be home. Not like his apartment with Bucky had been, and not Stark Tower had been.

The locks clicked shut behind him automatically, and Steve shucked his shield and bag onto the living room table before wandering into the kitchen to grab something to eat. In the old days JARVIS would have kept the fridge ready with gourmet meals; now, if he wanted something like that, he had to buy it and cook it himself, but SHIELD did do him the favour of keeping the freezer fully stocked with ready-to-microwave meals. His throat closed up for a moment at the thought of JARVIS – and then he breathed through his nose, and put the thought out of his mind.

His tablet lay where he'd abandoned it this morning on the counter; he thumbed it on, and the NYT article he'd barely started reading popped up immediately.

Monday, February 17th, 2014
STARK TOWER GOES DARK

Last night, at 3:42 AM, the lights on New York City's tallest building went out. Its arc reactor – the revolutionary, ultra-secret technology that the late Tony Stark had claimed would change the world forever – has run out, three months before its projected deadline.

"The building has already been reconnected to the city's power grid," lead federal investigator James Gallaghan said this morning in a brief press conference. "The arc reactor was designed to power the Tower for a year. In the days after the Chintauri Invasion, Stark Industries provided power to nearly half the city. They were aware that this would shorten the lifespan of the reactor accordingly and disclosed this information to us at the outset of this investigation."

But the windows on most floors of Stark Tower remain dark. Stark Industries, once a corporate titan, is no longer listed on any stock exchange. An estimated 99.8% of its assets have been frozen or seized by governments both foreign and domestic. Nearly six hundred thousand former SI employees are currently looking for work – but no one is eager to hire anyone who worked for the creators of the nanoplague. No one is eager to occupy the levels of Stark Tower, either. The Avengers, Stark's burgeoning team of superheroes who came together to save the city nine months ago, relocated just before Christmas; the last sub-letting office, Dyson Printing Inc, moved out last Thursday. The only remaining 'tenants' are Gallaghan and his army of investigators, who are still combing the former NY corporate headquarters for any clue that might shine light on how or why the nanoplague was created – and how it can be stopped.

It's an investigation that has come increasingly under fire from the international community as the nanoplague's death toll rises. The cover-up of Stark's suicide was orchestrated by a US government agency; the first outbreak didn't occur until days after his death. While SHIELD claims the creation of the nanoplague was solely the work of now-internationally-wanted terrorists Tem Borjigin and Maya Hansen, there is no denying that its development took place within SI facilities. Leaked reports from within the agency have pointed to Stark funding the project personally.

The public pressure is beginning to add up. A recent NYT survey showed that 74% of responders believed Stark must have had a greater role in the development of the technological virus than SHIELD is willing to admit. 36% went further, agreeing with the opinion that Stark's still-unconfirmed suicide was related to the nanoplague. For experienced political watchers, this is just the tip of the iceberg. Meetings on...

There was a knock at his door.

Steve stood and carried the tablet back into the living room where his shield was, switching the screen over to bring up his apartment's security cameras instead. If a reporter had managed to get past the outer security again – but, no.

The man waving unerringly at the hidden camera was tall, maybe only an inch shorter than Steve, mid-twenties – though the backpack he was wearing made him seem younger – blond, clean-shaven. He didn't seem to have a camera or mic – but then, if he was familiar enough with stealth surveillance tech to locate the one hidden over Steve's door, the lack of an obvious camera didn't mean anything. There was something about him that seemed familiar – something that was pinging alarm bells in Steve's brain. He gave the guy another once-over: sneakers, cargo-pants, sporty jacket – nothing that stood out –

Blond, clean-shaven – but his skin didn't really match the shade of blond –

Steve's brain helpfully imposed a goatee over his visitor's face, and he dropped the tablet back onto the table. "Son of a gun."

Another knock. How had he gotten past the front door? How the hell was SHIELD not picking this up? No, those were stupid questions. Steve grabbed his shield and threw open the door, tugging the guy inside quickly and letting the door fall shut.

"Steve!" Tony – a Tony – said, smiling brightly.

"What reality are you from?" he demanded. "And why are you here?"

The Tony's face fell, and his eyes slid off to the side. "Uh, well – okay, I deserved that."

"What?"

His eyes flicked back up to meet Steve's. They didn't match his hair either – too dark by far. This close, Steve could see the faintest beginnings of dark roots beneath a dye job that would have made Natasha frown with professional disapproval. "Um. I'm... from this reality."

Steve stared at him.

"Hi?" Tony offered, smiling weakly.

"You – " Steve set his shield down and glared at him. "You complete – bastard."

"Surprise?" Tony sighed, and lost the smile. "If I could have told you earlier – " he raised his hands, as if in defense, and then dropped them again, back to his sides. "But I didn't think – "

He broke off with a not-quite squawk when Steve stepped forward and pulled him into a hug. "You idiot," Steve growled at him after a long moment. He couldn't quite bring himself to let go just yet. Tony was alive – real, solid, warm. Living. Blond, for some reason. "You – bastard."

"I – um," Tony mumbled into his shoulder. He'd tensed up when Steve had hugged him, but now he was slowly relaxing. "I couldn't tell you earlier. It took me a while to – uh, to get back – "

"You lied," Steve stepped back, releasing Tony from the hug, although he kept a grip on his upper arms. He couldn't quite bring himself to let Tony out of reach just yet. "You said you'd be right behind me – "

"I was supposed to be!" Tony protested. "But the ring portal – broke, and then I had to use the one I cooked up for you – "

"You said you'd be right behind me," Steve said again, resisting the urge to shake him. "I spent four hours watching a corpse and half-thinking it was you, damn it – most of SHIELD thinks I've completely lost it, and you – you're – " He stared at Tony, not knowing how to put in to words everything in the last two and a half months, grief and worry and fear – "You're blond!"

"Yeah, I dyed it," Tony said, seizing upon the new topic eagerly. He raised one hand to push half-heartedly at Steve's hand and, equally reluctantly, Steve dropped that one back to his side. He kept the other hand on Tony's arm. "It makes me look like an idiot," truer words had never been spoken, in Steve's opinion, "but I think we already proved pretty conclusively that shaving is an insufficient disguise – "

"The growing four inches and losing twenty years helps," Steve deadpanned. Humour, because he hadn't the first clue what to think of it – and because the relief was making him feel giddy.

What in God's name had happened to him?

Tony's face crinkled with indignation. "Ten years – "

Steve rolled his eyes.

"Fifteen years – " Tony amended, still so full of bullshit, and Steve grabbed him and hugged him again. " – and glad to see you too – need to breathe, breathing, Cap, s'good idea – "

"I thought you were dead," Steve mumbled, and he felt/heard Tony sigh before the other man brought up his arms to hug Steve back. "Again."

"I'm not sorry," Tony said, half-hearted and tired. "It was for the best."

The words felt like a punch in the gut. Steve let him go and backed off, retreating around the table. How could Tony think that? What the hell had he been doing? "How are you – what happened?" he asked instead. "Magic? Some sort of spell? Did Anthony come back?"

"Ah – no, no, and no," Tony said, his eyes sliding to the side again. Oh, Lord. How bad was it if Tony wasn't even trying to lie about it properly? "Which I'm sort of worried about – I did eventually manage to get a ring portal active, obviously – go me, fixed that problem, but it took a while to rebuild and I thought he'd get to it sooner – "

"Tony," Steve cut him off. "What happened?"

Tony didn't reply – not verbally. But his gaze flicked over to the tablet, still lying on the table; Steve followed his glance, and watched as – apparently of its own volition – the screen turned on and the security program flipped back to the newspaper article he'd been reading.

...Today marks the twelve-week anniversary of the release of the nanoplague. According to estimates from the WHO, nearly 90-million people have been infected; more than half of those are now dead. But the total indirect death toll is even higher. As countries close their borders and put up armed guards, international trade and travel has ground to a halt. Aid to quake victims in Southeast Asia has ceased almost entirely, with shipments of food, building, and medical supplies backed up at international borders. Refugee camps in the Middle East make tempting targets for the so-called 'super-zombies'...

What? And also – what? How was Tony controlling the tablet? JARVIS? Steve felt his heart give a lurch of hope at the thought.

The article scrolled down, and then clicked over to the next page – and then the next. The words stood out from the screen: ...hidden funding beneath Stark Medical, leading to some speculation that the purpose wasn't to create super-soldiers. Dr. Elizabeth Dean, professor at the University of Philadelphia, is one of those who thinks that extremis' original purpose was non-military. "The unique thing about it isn't that it makes its victims mindless – plenty of conventional drugs can do that. But the astonishing healing factor – "

Oh, no. Healing factor? Tony had lost two decades and grown whole inches.

Healing factor. Human enhancement.

"No," Steve said. "You didn't." He couldn't have, could he? Extremis didn't work – that was the entire problem, it was broken, it turned people into zombies

"In my defense," Tony raised his hands, a half-hearted attempt to placate, "I was dying, or – close enough to it, anyway."

Steve stared at him.

"I got – attacked." He shoved his hands in his pockets and stared back at Steve mulishly. "It was your idea?"

"What?" That came rather closer to a shout than Steve had intended. "It was not – "

"Well, okay, I could have been hallucinating that, like I said, I was dying – "

"Who attacked you?" Who had been left? Had ULTRON come back to life somehow? Had Natasha betrayed them? He quashed that thought immediately. He hadn't been wrong about her – he hadn't.

"Somebody from that reality, nobody you've... met," Tony said, but he was obviously hedging. He met Steve's eyes and smiled ruefully. "It's complicated – more complicated than I told you. I... couldn't say everything, not then. I still can't. Somebody might hear – I'll tell you about that, though, too, because," he picked up the tablet triumphantly, "I can write it out, and we can go over this on the way. I'd like to get going – we're wasting time."

"Time before what?" Why was he here? After months of letting Steve think he was dead – of letting everybody think he was dead?

"I infected myself with extremis," Tony said bluntly, meeting Steve's eyes challengingly. Whatever he thought he was going to see there – Steve didn't know, but Tony looked away, down at the tablet instead. He switched over from the news to the interior cameras – SHIELD was honest about placing them, at least, even if Steve hated them. Tony even bothered to tap the controls with his fingers, this time.

"For some reason, I didn't go crazy," Tony continued, now quiet. "I didn't get the, uh, full superpowers, either. I mean, I tried, I was dying anyway, I figured, why not grow three inches and run faster than sound? – but whenever I reach too far, it starts... getting loud, in my head." He shuddered, and it looked like an unconscious motion.

"You infected yourself with extremis," Steve said flatly. It was a stupid thing, echoing Tony like a parrot, but it was say it or go over and bang his head against the wall until Tony's actions started making sense. Who, even while dying, thought the answer lay in zombie-hood?

"But I'm not a zombie."

"I can see that!"

"When I figured out I could, I recoded parts of it," Tony explained, hurrying a bit more now, "While it was recoding me, so it was kinda a rush job. Some... I couldn't. I firewalled it off – there's these linkups out there, it's a hive-mind – something I never designed. I've been trying to hack into it, see if I could gain control of the network and make it stop, but I go too close and it becomes hard to think." He grimaced.

"And it's getting worse?" Steve extrapolated, even more alarmed. With the rate the nanoplague was spreading –

"What? No," Tony said, apparently startled that it was even a consideration. "I told you, firewalls. That's not the point - every minute, more people are becoming infected, more people are dying. I've tried to stop it." His expression, for all that he was obviously struggling for composure, was one of muted anguish – and then, like a switch had been flicked, that composure was achieved and his voice became calm, earnest. "Please believe me, Steve, I have tried. But this tech – it's beyond me. I hate to admit it – Jesus Christ, I hate it – but it is. There's too much I don't understand of it, too much weirdness that Borjigin tossed in – you could even say alienness." He raised his eyebrows significantly.

"You have a plan," Steve said, because he had to – it was Tony, after all. And he was here.

"Maklu owes Earth wergild – I propose we ask them for the cure. I've built a portal that can take us there. I want you to come with me." His gaze was frank, direct. "Promised you I wouldn't do this alone."

Steve rolled his eyes, and, stubbornly, took a seat at the table. "Why not involve SHIELD?" Because that was a damn thin line for Tony to be treading, after six months of being admittedly hallucinating and paranoid, and another ten weeks of nothing.

"Bigger organizations, bigger risks – come on, you know that he has his fingers inside it, I know you know that – I read the reports, Steve. And I read your report, too – you never told me that part where you went and chatted up the Chief Magistrate – "

"You could go directly to Fury. He'd keep it small, within the team – "

"What, and give Fury the perfect scapegoat? Waste six months trying to prove my self from an alternate reality was the one who fucked us over?" Tony snapped. Steve narrowed his eyes; the other Tony might have triggered the Skynet Protocol, but it had been Tony who had hired Hansen and Borjigin... and who had regained the memories that had driven him crazy shortly before Steve had last seen him. He'd said that it would be fine, but how far could Steve trust that? "Not worth it. Bruce is a problem – I can't shield him, he's a... beacon," Tony said, fumbling for the word. "He stands out, and everybody nearby him stands out. So. I take you, that leaves Clint and Natasha to stay here – you know they work best as a team."

"Rhodey – "

" – is about one step away from being court-martialled and today's stunt didn't help things. He's too close to me." Guilt, in his voice and in his eyes. "There're too many people who want to take the armour away from him and I'm not going to be the reason they strip his rank trying."

"Thor could – "

"Names," said Tony, and it was half a snarl, although his expression was completely, perfectly controlled.

Steve frowned at him, searching his face for some kind of break or clue. "You said - and Anthony said - it was like... calling them, right? He's an ally, even if he isn't... here."

Tony waggled his hand it from side to side, easy-going again. Normal. Frankly, kinda freaking Steve out. "Yes, sort of, though you're jumping the gun, I was worried about, well, nevermind. Call their name and they get a ring, fine, let's go with that. Ally, though – not so much." There wassomething off about his expression, a kind of brittle blankness that made Steve reach for his shield so he could run his fingers along the edge of it. "So. Not him. I'll explain on the way." The whatever-it-was in his expression smoothed out again with the return to the topic of leaving.

"You're in a hurry."

"Steve." Now it was Tony's turn to frown at him – though, being Tony, he frowned by raising an eyebrow. "If somebody in Maklu can explain a couple key points about their tech, we could shut down extremis tomorrow. That's anywhere between fifty thousand to ten million lives saved."

That was... a very good point. Steve fought against the shame that washed over him – he still had valid reasons to object. "So it's just you and me, off to demand a favour from aliens on the behalf of Earth? We don't have that kind of authority, Tony."

"You want to leave this up to bureaucracy?" Tony said incredulously. "Steve, there is no time - "

"There was time, these last two months there was time!" Steve said, planting his palm on the table and leaning toward him. "You could have contacted us at any point – "

"That would have wasted time with – "

"That's a damn poor excuse, and you know it! You walked in here without being seen, don't tell me you couldn't have contacted SHIELD without handing yourself over! You could have kept us in the loop – we could have had this conversation two months ago!" He was standing, he realized – the chair was lying on the ground behind him, tipped over. He hadn't realized he'd stood – he grit his teeth, and this time it was directed at himself. He needed to get his temper under control. "You told me," he said, taking care to keep his voice even, "You promised me you wouldn't keep trying to do this alone."

"I'm here, aren't I?" Tony shot back, almost petulantly, and he immediately made a face, apparently realizing how childish he sounded. "SHIELD is compromised, Steve. I couldn't even trust the EMR shielding I had, because they took it and he took it from them, he's been toying with them – so who knows if he figured out how to get around it? This is new stuff," he waved a hand about, as if to indicate the invisible shield present. "Not to mention all the other – look, that's not important. SHIELD has no reason to trust me and every reason to get in my way, and this is too important for that."

"Pride goeth, Tony," Steve said tightly.

Tony let one corner of his mouth quirk up in a small, sad smile. "I know. Will you come?"

Steve sighed. "Of course I'm coming. Let me pack."

"Don't bother with the suit, I've got a better one for you," Tony ordered, doing an abrupt one-eighty from muted disappointment to looking as pleased as a cat. He leaned – more lounged, really – against the back of a chair, tapping his fingers rapid-fire on the wood. "Saw your fight earlier – that was ridiculous, you shouldn't have to worry about fire."

That left – not a lot to take. He grabbed his coat and shoes, a water-bottle and some snacks – which he tossed at Tony; if he was going to impersonate a college student by carrying around a backpack then they might as well make use of it. Tony, though, didn't put them away, just stood there holding them with a bemused expression.

"I have to leave something for SHIELD," Steve said, going over to hunt around in the drawer for a pen and pad of paper. "They thought I was crazy the last time I came back."

"I can write one in..."

"And then you'll have to tell them you were here," Steve pointed out. Left unsaid was the question of whether or not Tony would actually tell them, even now.

He clicked the pen and scribbled down, Gone to Maklu to get help with extremis. Please water my plant. Not sure when I'll be back. Tony – not to mention JARVIS – might be able to hack any electronic device he set his mind to, but paper would hopefully be harder.

"I hope you have a flying car," Steve muttered, checking the exterior cameras on the tablet. There were only three news teams camped outside today – when he'd first moved in, there'd been thirty, and after the one time he'd made the mistake of leaving by the front door, it had briefly increased to something that felt like three hundred. These days, he got SHIELD to drop him off on the roof – it wasn't as if he ever went anywhere except where SHIELD pointed him. He'd have felt sorry for his neighbours, except that they were all SHIELD agents, too, and half of them were probably tasked with keeping an eye on him during their downtime. He felt sorrier for the news crews, really – it was pretty clear that none of them actually wanted to be there, standing out on his doorstep in mid-February weather. In the beginning, sure, there'd been some keeners; by now those remaining were low-level reporters assigned the crap job by the higher-ups. But that didn't mean he wanted to make their day by walking out his front door where they could get a shot at him.

Tony rolled his eyes. "If I had a flying car I'd have showed it to you months ago."

True, Steve had to admit. "I'm gonna get mobbed as soon as I leave."

"Nope." Tony grinned, and strolled out the door, calling from the hallway, "Come on, Cap! Let me show you some science."

Steve eyed the door, then the paper – still there, still with words on it – and followed him out, letting the locks click home behind him. Tony, looking as energetic as... well, as energetic as Tony in his twenties must have been... practically bounced into the emergency stairwell and down the stairs. Steve had a sudden bad feeling about this – or a worse feeling, at least. When they got to the bottom, Tony held out his hand, wiggling his fingers in invitation. "You'll love this."

Steve raised an eyebrow, but took his hand; Tony interlaced their fingers, like they were teenagers out on a date, and Steve rolled his eyes. "Science?" he asked pointedly.

"Yup," said Tony, and the world grew... brighter.

No, thought Steve, looking at the shockingly vivid blond of Tony's hair – the brilliant scarlet lining of his jacket, no longer muted – the deep chocolate-mahogany of his eyes – it wasn't brighter. But all the colours were suddenly vivid like they'd never been before, and in that moment he wished more than anything that he had pastels with him and a blank canvas, so he could try to capture even a tenth of what he was seeing. His breath caught, stolen by the world's new beauty.

"Invisibility cloak," Tony said smugly. "I upgraded it, too – it's covering both of us, at the moment. When we get near the door I'll include it, too, so it'll look like it stayed shut – no mysteriously opening doors."

"This is amazing," Steve marvelled, looking down at him himself. His own skin was pale, was rosy, was practically glowing; the blue fabric of his jacket was like the sky on a cloudless day, out in the middle of the wide-open Midwest. Even the boring stairwell walls were transformed, every shade and shadow on their imperfect surface suddenly a masterwork of art.

"Still guzzles gas like a Ford, but the aliasing was reduced by 83% on average, so I'm calling it a win," Tony continued as he dragged them over to the door. "You good to go?"

"I want to look outside," Steve said, feeling a smile tug at the corners of his mouth.

Outside was brilliant, and not just because it was the first time since he'd moved in that Steve had been able to walk out his own front door without immediately getting mobbed; the news vans were set up outside, but the reporters stayed huddled near the doors, completely ignoring Steve and Tony as they wandered down the sidewalk. Steve barely paid them any attention at all: he was caught up in the colours. Had he ever seen a sky that shade of storm-grey before? The pathetic little trees planted by the sidewalk were transformed; the wrought iron grating over some windows had never been more foreboding; the rich reds and browns of the bricks had never before displayed so many hues. He almost didn't notice when Tony came to a stop beside a small car – green, deep green, like the ancient trees in the –

Then everything faded, and Steve had to stifle a noise of protest. Normal, he reminded himself – Tony had just dropped the cloak, so this wasnormal – but compared to before it was like watching the world in grey-scale. Everything seemed less... real, somehow.

Steve shook his head. That was a dangerous thought.

"Yes, hard to believe, I know," said Tony dryly, pulling the door open for Steve – of course, of the two of them, Tony was the less recognizable now. "But it makes up for it in that it's inconspicuous."

"Tony Stark, back from the dead, driving a Volvo," Steve muttered, as he slid into the car – the seat was uncomfortably short for somebody with legs as long as his – and pulled the door shut. Tony went around to the other side, and when he'd climbed in, too, Steve finished, "Nobody'd believe it if I told 'em."

"It could've been a minivan," Tony said, with real distaste.

"That I can't believe."

"Yeah, you're right," Tony agreed. "It couldn't have been." He pulled out onto the street without bothering with his turn signal and then almost immediately made an illegal left-turn into an alley.

Steve clutched at the door-handle. "Is this car secretly a tank?" he yelped.

"Cameras, Steve. Cameras everywhere. Seriously, nobody expects New York to give London a run for its money, but hey – things the government doesn't tell you, huh – the point is that I don't need to look to tell when there are cars coming. And the car has its own cameras, too, and enough of a computer that I don't actually need have my hands on the wheel."

"What, cameras? Don't tell me you – "

"I told you I took extremis, Cap," said Tony, an just a tiny bit too calmly. "And that it worked for me. I can see – lots of stuff, now. The whole of the internet – it's a trip, it really is." His grin didn't reach his eyes. "Everything wireless, lots of things that aren't – everything that's a computer, it's mine. How did you think I was controlling your tablet? I wasn't being subtle, for chrissake."

"I thought JARVIS was helping you," Steve said, sharp, too sharp, and he had to turn his head away, immediately regretting the words – more so, at the sound of Tony's soft intake of breath. The car careened around another corner and into traffic thick enough to force Tony to slow, at least momentarily – even if extremis had enhanced his reaction speed, there still needed to be a gap to move through.

"JARVIS is dead," Tony said quietly. "He died months ago. I could bring back a copy of him, but – he'd be a new person. New JARVIS – sibling of old JARVIS, but... new. Dead is dead. Sometimes undead." He grit his teeth together hard enough that Steve could faintly hear them grinding.

New JARVIS. Dead is dead. The JARVIS whom they'd brought online after the other Tony had killed himself, when everything had first gone pear-shaped – had he just been a copy?

Didn't matter, even if he was. There were a million copies of Steve running around out there, each in their own alternate world – they were still all separate people, and most importantly, they were all people. There was nothing about the JARVIS that would ever make any version of him just a copy.

A gap in the traffic – Steve registered it, and then registered Tony accelerating a moment later, swerving and through, earning himself a loud outcry as at least three other drivers leaned on their horns. Hardly keeping a low profile – Steve glanced around for cops, but of course, there weren't any. Tony would have seen. But if there were cameras –

Okay, so that was taken care of, but if somebody phoned –

...but if somebody made an actual, in-person report, then they might get noticed by somebody with the authority to do something about it. It would take a while, though – they'd be long gone by then. Assuming that they didn't wind up in a car accident, with a car banged up so badly that they weren't able to go anywhere.

"It still wouldn't kill you," Steve managed, "to drive with a bit of sanity." He would have sworn that Tony's driving hadn't been this bad before.

Tony's mouth twisted; his words were a bit too tight: "Don't tell me you obeyed all the rules of the road back in Germany."

"Back in Germany I was trying to avoid enemy fire, not red lights. Getting in an accident isn't going to help anything!"

Tony sighed, but he eased his foot off the gas pedal, at least, and then instead – Steve covered his eyes with one hand – leaned all the way over into the backseat, taking his eyes off the road, to fish out the tablet from the backpack and toss it into Steve's lap. It made a chiming sound of activation when it landed, and Steve turned it over to see red text on a black background reading, Question and answer time, then. Beneath the text was the outline of a keyboard's keys, white-on-black.

Steve placed his fingers carefully – this type of keyboard really wasn't meant for people with hands as large as his – and paused. There were so many questions he had to ask – where was he even supposed to begin? Well, he could start with the mundane.

He felt reluctant to bring up JARVIS again, so quickly. And what was he supposed to say about the whole damned mess, anyway?

"How long is this trip gonna be?"

"Ah," Tony said a bit guiltily. "Well. The facility's out in Lima."

Steve stared. "Lima, Peru?" Why were they driving?

"No, Ohio."

Okay, that was... not quite as bad, but it was still at least an eight-hour drive – probably more. Steve closed his eyes and thunked his head back against the headrest.

"The car's got enough stealth tech on it that I can speed well above the limit," Tony assured him, which was not actually reassuring at all.

"Why not a jet?" he asked instead, skeptically.

"Because I haven't gotten around to stealthing one of those," Tony shrugged. "It's a bit more involved than a car. And it's sort of hard to go unnoticed at the airport these days."

That was true. Steve looked out the window as they idled in a sea of cars at a red light; an enormous electronic billboard was flashing a public health advisory, reminding citizens to Keep Yourself Safe from the Nanovirus: 1) Avoid international travel until the crisis has passed... – pretty dumb advice. All non-military air travel had been shut down for months; countries had closed their borders as tight as they could go. Consumer airlines were being kept afloat by government backing, and nothing else.

But that wouldn't have been a problem if Tony hadn't still been keeping everything secret from SHIELD – with a quinjet, the trip would have take less than an hour. For all he'd been going on about hurrying, Tony valued secrecy more than he valued stopping extremis right now. Steve felt the corners of his mouth turn down at the confirmation.

What couldn't you tell me back in the other world? he typed out. His text came out blue.

The cursor hadn't blinked more than once before the reply appeared: Asgardians aren't human.

"Huh, I'd never thought of that."

Ha, ha. They're reallynot human. They don't exist in space and time the way we do.

Steve blinked at the tablet. That sounded... kinda crazy, even when talking about aliens. Thor had been right there – so had Loki. But more text was already appearing with explanations, so he read on: You've seen alternate worlds – humans on alternate worlds, they're just other versions of us. They're not the same people – very similar, but we don't have a hivemind. Asgardians do.

"What?"

The Nine Realms are all alternate realities of each other – sort of, Tony wrote, which didn't help clear things up at all. Without being... alternate alternate realities. Basically, if you took Earth and cloned it a couple of times back at the dawn of the planet and allowed for the space-time-'magic' differential fall-out, you'd get the Nine Realms. Then you take the Nine Realms and you clone them altogether, and you get a bunch of different alternate realities, like the one we were in.

Then, you take all those alternate realities – let's call them a Cluster. So you have Earth, then the Nine Realms, then a Cluster, and Clusters can be copied over and over, too. They're all copies, just with different types of variations depending on what dimension they're being copied along. Generalized Foster Theory holds that there's an upper limit at the number of dimensions, and Asgardian science agrees, but a GFT says that some of those dimensions are infinite, while Asgard's science says no, they're all finite. Well, sort of. Thor's explanation got kinda mystical-mumbo-jumbo at that point, I'm not sure if he didn't get it or the SHIELD scientists interviewing him didn't. Waste of time, really, they should have let Foster do all that questioning.

Vaguely, Steve remembered Sue Richards explaining this – but somehow, the explanation had made more sense before Tony had pitched in, when he hadn't had to think about it too hard beyond the fact that alternate realities were somehow real. Plus, he'd been distracted with all their mentions of gods at the time.

"Um. What?"

Tony sighed. ...Think of Earth like a marble.

"Okay."

Although it's not just our Earth, it's our... 3D universe. The solar system, the galaxy, everything you could fly a spaceship to - it's all one marble.

"...Okay."

Now, there's a bunch of other marbles all like, but they're... I don't know, different in size or shape, or whatever. They're similar – they're made out of the same stuff – but they're... uh, different. And if you wanted to get from one marble to another you couldn't just walk around on your own marble. You'd have to, hmm, hop.

Tony was pretty bad at metaphors, Steve thought, but he nodded anyway.

Well, you... keep marbles in a bag, right? One of those little netted things. Okay, so you've got a set of marbles in a bag. Those are the Nine Realms. There's more than nine marbles, but nothing humans have ever named after numbers is accurate – look at the Hundred Year War.

"Tony."

Right, off-track. So you have a bag full of marbles. Now... imagine you're a marble store. You sell lots of sets of marbles! So you have an entire stockroom full of bags of marbles – that's the Cluster. And... if you're a chain marble store, then you've got other stores elsewhere that have their own rooms full of marbles, and those are other clusters. But compared to getting between marbles within a bag, or between bags within the same room, they're... really far away. It takes a lot of power to travel from one to another.

"Okay, I get that," Steve said. "I don't understand why it's... important. It's still – " he caught himself, and typed, It's still an alternate reality.

Humans exist on a single world, Tony replied.Your alternate reality self – he's not you. He's just a guy like you. But Asgardians exist over Clusters. The interaction between one world and another can be limited – but they're all the same person. The Thor back in the reality we visited is the same as the one here – they're different personalities, appearances... but there's a connection between them. They're the same person, in the end.

"How does that work?" Steve eyed the tablet, and then, realizing that was a bit ridiculous, eyed Tony in the seat next to him. "How do you evenknow that?"

In every Cluster, every marble store, there's one central, prime set of Nine Realms – um, like a really expensive, rare, prized bag of marbles, the sort that marble geeks would go crazy over – where all the information from the other alternate realms within the Cluster gets... stored, sort of. Condensed. The prime-Thor there is the realThor – the one here is more like a reflection of some parts of his personality. Not all of them.

That was... hard to picture.

The Clusters cycle based on Ragnarok. It's another Norse myth – regrettably way truer than I'd like –

"I read up on it," Steve interrupted.

Well, it's real. But it doesn't just affect Asgard, or any single set of Nine Realms: it's Cluster-wide. There are these beings – the Asgardians call them the Norns – they... determine the fate of the Cluster, I guess. Or maybe just all the Asgards within that Cluster – I'm not too sure, ever since you mentioned other gods... but, well, anyway. They control a lot of something. Loki-prime from another Cluster wanted out – in his Cluster, he was fated to die at the end of Ragnarok – so he pulled me from this one. That's when I learned this. Most of it, anyway. Some of it's still guesswork. He needed an outside agent in order to get around the Norns' power, since they had total control over all the rules withinthat Cluster.

"And?"

"He succeeded, of course," Tony said, sounding a bit annoyed. "I told you that already."

Memory came back to him with perfect clarity: looking upon Amora with Stephen's gem, and seeing her selves branch out – across worlds, across realities, all connected, all luminous and powerful, the truth of a goddess' soul: beyond any human comprehension. "I meant, what are you planning to do about it?" If Tony was still planning on killing Loki – how? Going to each world, out of who-knew how many worlds there were in such a 'Cluster', and killing each Loki there?

Cut off the head, and the body follows. If I kill the alternate Loki in the prime set of the Nine Realms in this Cluster, where his true self is located, all of him dies – and the spell he worked to destroy his original Cluster will collapse. Ragnarok unwinds, the universe rebuilds... I don't know what happens to the other pantheons over there. I'm... almost dead certain that the entire Cluster was destroyed by what he did, not just Asgard.

That's what the pantheons here are worried about, Steve typed out. It had to be. A force coming from outside the universe – outside their Clusterof universes – one that couldn't be contained by the forces in this one –

"I think so," Tony agreed aloud. He glanced over at Steve for a long moment – his eyes off the road the entire time, of course – before adding, "Think you want to fill me in on what you left out for your report to SHIELD?"

Steve hesitated. Bringing a murderer to justice, a murderer of... Lord, who knew how many people – how many copies of the Nine Realms were there within a single Cluster? – surely, the Other Loki's victims deserved justice. But if Tony had wound up creating extremis in pursuit of that goal – extremis, or other world-breaking weapons, as he'd admitted – there was a line to be drawn. True justice did not call for innocents to be sacrificed in its name.

But this wasn't just revenge. Tony was far from the only one making preparations; an entire universe – multiple universes – were on edge about an invader, readying themselves for war. If Tony had screwed up – and he had – then he had done so with the best of intentions... which still didn't count for jack squat in the face of the dead, but that hadn't been entirely within Tony's control; far from it. And what mistakes he had made – in trying to do it all on his own – well, at least Tony was stretching out a hand. Steve had to reach back.

So he said, "All right," and told him, starting with how Anthony had appeared in the workshop. Parts of this he'd told Tony before, back in that other, darker world; much of it had gone into his report to SHIELD; but now he left nothing out except for what he'd been doing in the workshop in the first place. Anthony; Susan and Reed Richards; his own alternate self. The strange, other Stark Tower with its top floors missing and an even stranger structure floating in midair next to it. Rhymes and magic, chants and spells, all the advice of two different sorcerers, and the gem that had been able to see souls.

The telling took them a considerable distance into Pennsylvania, especially since he had to type out so much of it – Steve didn't think the soul gem was something that should be discussed aloud, and Tony seemed to agree. He asked detailed questions, instead, about everything from layouts to the details of the runes that Anthony had used, which Steve did his best to draw, although with the serum having been neutralized at the time his memory wasn't as clear as usual. The task of recollecting it all wasn't made any easier with the way Tony drove like an absolute lunatic, swerving through gaps in the highway traffic so narrow that Steve found himself reaching for his shield.

It was for a good cause, he reminded himself firmly.

"I hate magic," Tony sighed when Steve was done.

"It's not all evil," Steve defended.

Tony shook his head. "Not what I meant. I mean – magic, the idea of it, the idea it can't be understood – " there was a deep frustration beneath his words, a dark, ugly thing that Steve took careful note of. "I'm going to figure this out, how it works." He took a breath. "But first, extremis."

Steve glanced out the window, at the traffic around them. He didn't travel on highways enough – or at all, really – to know if the number of trucks and cars on the road was normal. Without air travel, were more people going cross-country by land? Or were they all staying put for fear of the nanovirus? He knew there were ongoing problems with mail delivery, but he'd had other worries, and the post situation wasn't one that he could help.

There were more than enough vehicles to make the way Tony casually wove in-between lanes absolutely hair-raising. They nearly side-swiped a semi – well, its tires – and something crunched in Steve's grip.

Tony glanced over. "I guess you wouldn't need the handle to open the door anyway."

He stuffed his hands back in his lap. The tablet might be wholly Stark-made, and therefore no doubt superior in every way to the car, but he didn't want to risk it.

The silence was awkward. All the late-night conversations they'd used to have – eventually become day-time conversations – hadn't been easy at first, but after months, they'd grown natural. But now... what was he supposed to say? While Steve had thought they'd been becoming friends, Tony had been hiding the fact that he'd been going crazy, and building secret evil lairs and death-machines. The chatter and humour made Tony seem like a bright spot of familiarity – but he was a stranger all the same.

Steve locked his hands together and brooded. The silence drew out – he'd have thought it would just become silence, but the minutes dragged by and it didn't get any less awkward. Probably because he still didn't have any answers to the questions that mattered the most – he wasn't certain he even knew what those questions were.

Trust Tony to turn his world upside down again.

"Well, this is awkward," said Tony brightly after about fifteen minutes.

"Pepper and Rhodey think you're dead, y'know." Steve felt guilt bite at him, and shoved it away – the fact that he hadn't really been planning to say that didn't mean it wasn't true.

"It's safer for them that way." Tony was calm, matter-of-fact. "Safer for me, too."

What – "Either one of them would die for you," Steve growled. "Tony, they're your best friends!"

"And that makes this situation shitty but doesn't change it. I can't do that to them, Steve. If Natasha hadn't gotten Pepper out – well, it didn't come to that."

So it had been Natasha.

"Rhodey's still in, though. And he wants to stay in. The Air Force is his life." Tony's voice dropped, going quieter. "I've dragged them both down far enough. I'd like to think I'm not such a shitty friend that I can't let go before I hit rock bottom."

"That's not how it works, Tony."

"I know. Hey, you're here, just like you asked."

"I shouldn't have had to," Steve said, exasperated.

"You didn't."

Steve blinked. Tony's grip was loose on the steering wheel – he'd returned to that same easy calm. Too easy? Maybe slightly robotic. It didn't make any sense. If Tony had been willing to come and ask for help – or at least to accept that he didn't have to do this alone – then why hadn't he done something before now? He'd had weeks.

"Tony..."

"Oh hey, look, a Burger King," said Tony, the cheer in his voice so genuine that Steve almost believed it. "I haven't been there in ages!"

A few hours later, the greasy drive-thru burgers sat heavily in Steve's stomach. He should have known it would be a mistake, he thought, suppressing a groan as he wrapped his arms around his middle. It wasn't like he was actually sick – the serum wouldn't let a bad burger get him down – but the strange chemical taste of it left him feeling like he should be.

It wasn't that he wasn't used to bad food, or even highly processed food – rations during the War had been fuel, and generally only edible by accident. But at least that was a familiar bad, learned over years of being poor in the Dirty Thirties. In Stark Tower he'd been spoiled – organic everything, meat of the finest quality cuts, take-out from places that wouldn't have done take-out for anyone else... he just wasn't used to the weird flavour of Fast Food America.

Or maybe the burgers really had contained poison,he thought grimly, as they swerved way too fast around a tight corner and his tongue recalled the uncannily alien taste of the bread.

The tiny, one-lane road they were on now wasn't even paved! They were lucky they hadn't skidded right off –

"Tada," said Tony, as they pulled around a last turn, the high-beams revealing a narrowing of the road toward a small mine entrance, now covered with chain-link to keep anyone out. Anyone like... them; Tony was not slowing down, and Steve nearly reached over and ripped the wheel from his hands – "It's an illusion, Jesus, relax."

Steve grit his teeth anyway as the entrance drew nearer: the chain-link wasn't too imposing, but even a Volvo wouldn't have fit into a tunnel that size. Passing through the image wasn't like holding onto Tony while the ICG kept them hidden; instead of all the colours becoming more real, everything blurred together instead, reminding him briefly of being fever-sick with extremis, when nothing he'd seen made any sense. Then they were past it, driving through a tunnel leading straight into the hillside. It went in only a short ways, but when Tony pulled to a stop and killed the engine, the place was pitch-dark. In daylight enough light might have made it through the entrance to see by, but it was now a cloudy night. Or would daylight have been enough? Would the illusion at the entrance have prevented it from coming through anyway?

There was a clicking noise, and a strange type of sound that Steve couldn't quite place, and then Tony was visible, a small circle of light coming from his right hand as he got out of the car – he'd put on a repulsor at some point, and was keeping it powered just enough to show their surroundings without actually firing a beam. It looked like the entrance to an old mine – not coal, but beyond that, Steve couldn't have said what it was anybody might have been digging for. It had clearly seen better days, though; the metal support beams were covered in grime and rust, the paint on the steel door set in concrete at the side of the small parking bay was worn almost entirely away, and the entire place had an air of... emptiness – the sort that an occupied building couldn't achieve.

Steve thunked his head back against the headrest several times.

The door was pulled open, and Tony stood there, shining his 'flashlight' into Steve's face. "Uh. You coming?"

"Get the damn light out of my face, and I will," Steve snapped, trying to keep a whining edge out of his voice. But Good Lord, what was it that drew Tony to creepy underground secret lairs? He almost opened his mouth to ask when he'd given up on things like the Helicarrier, the Tower – but clicked his teeth closed in front of his tongue instead. He wasn't happy with Tony's behaviour; that didn't mean he should be cruel about it.

"Next time you build a secret evil lair, just put it in a warehouse," he said instead. "Aboveground."

"Mines are good for hiding radiation," said Tony, with the air of somebody trying to explain the obvious.

"What?" Tony might be immortal – and now jacked up on Extremis – but Steve didn't have the benefit of Anthony's wards anymore.

"Not the lethal sort, don't worry," said Tony cheerfully. "Come on, I'll show you."

The elevator down was too new to have been the mine's original; the dull gleam of its steel was at odds with the rust and dust everywhere else, and even aside from that it just looked more... modern, less rickety than the rest. He wondered if the original mine entrance they'd pulled into had been intended for cars at all – but there hadn't been any rail-lines. He could fit what he knew about mining in a thimble, though. Heck, maybe it was a coal mine. He'd assumed that a coal mine would be dirtier, but that was probably a stupid assumption. No matter was being dug out, it was from a hole in the ground.

New or not, the elevator was meant for freight, and it was slow and jerky too. "I need to recalibrate this," said Tony contemplatively, as they rattled their way down. It was a long way down – at least as far as the complex under Shenzhen, and although that made sense, it didn't make Steve happy.

"Put some lights in, too," Steve suggested, as they came to a stop and the gaps in the wire doors revealed a pitch dark hallway leading away.

"Thought you wanted me to build a new lair in a warehouse." Tony glanced ruefully at his hand as he lifted it to illuminate the hallway, showing newer reinforcing beams covering the roof, mixed with obviously older supports holding up the walls. "Lights were... less of a priority.I didn't lie when I told you I was all out of secret lairs, before – I had to build this one from scratch after I got back. Well, almost-scratch. I had to redecorate it from scratch, anyway."

Steve shook his head. The sheer logistics of it... "Where'd you get the money?" He couldn't watch Tony's face while he answered; the ground was too uneven to keep walking without either paying close attention or tripping even second step.

"Markets are an easy play – seriously, people are idiots. Anybody with a brain comes along, boop, money just piles up."

"Markets are at the bottom of a pit deeper than this one."

"But still trading, which really doesn't contradict anything I just said."

Ahead of them, steel blast doors – Steve grimaced again – opened automatically, revealing yet-more darkness beyond. Tony shone his light around the room they stepped into, playing it over bulky metal boxes of computer equipment, cords everywhere – and thicker power cables, a half-dozen running up the walls to each of the many reflector panels positioned overhead. It was still completely dark.

"Portal Mark Four – energy-looping, biomass stable, sized for up to four adults or eight midgets," Tony said proudly, as a humming grew all around them – things turning on by themselves... or maybe that was extremis. There were still no lights.

"You sure about where we're going?" Steve asked, unslinging his shield and running his hands nervously over the edge.

"Yep, let me – dress you up, first," Tony said, changing directions mid-sentence. The light bobbed away and Steve turned his back instead of watching it go, letting his eyes adjust until the ambient allowed him to see a clearer picture of the room than when Tony had been waving the source around, blinding. Not that it was a much better picture – it was still too dark – but it gave him a better overall view.

It was big, bigger even than the portal setup in Shenzhen, which had dwarfed the one he'd actually seen in action in New Orleans. The reflector panels were so densely packed that they formed a layered half-sphere at the far end of the short, stubby oval setup. Unlike both of the previous devices that Steve had seen, this one didn't have a single laser – it had five, arrayed in a precise pentagon. Had Tony borrowed that idea from magic? Behind the lasers were two enormous, bulky machines that Steve couldn't make heads or tails of, except to realize that apparently they were meant to be able to move by means of tracks along the ceiling – one to swing into place and attach to the lasers while the other moved back to stay out of the way, or vice versa. So: the portal was what Tony had said it was, but the device could also be something else...

Footsteps hurried back; Steve turned, and caught fabric as it was thrown at him, and then nearly dropped it before he could get a grip on it. It was slipperier than silk. It couldn't be silk, could it? It was way too light.

"Strip, put that on," Tony ordered imperiously. "First layer – breathes like a dream, heat and cold resistant, and yes, I included undies. Now, this," he brandished a pair of pants that Steve couldn't quite see, not with how Tony was holding them up with the same hand that had the light source – Steve rolled his eyes, beginning to undress, and Tony declaimed, "This makes modern body-armour weep – it's the best you're going to get short of stuffing you into a suit, which, yes, I considered for this trip. Humans are squishy, Steve. This is three times as impact-resistant as SHIELD's best stuff, ten times as resistant to knives – creating it was easier than trying to sew it up into a suit for you, you have no idea. If by some very remote chance somebody actually manages to make a hole in it, it has self-repairing nanites, though it could take a while. Flame resistant, acid resistant, alkali resistant, just generally... resistant, here."

Steve pulled the underlayer's top half over his head, trying not to marvel at the feel of it against his skin; and he'd thought the sheets in Stark Tower were opulent. This was like wearing water. He grabbed the outerlayer pants as Tony tossed them over, too, hopping on stocking feet to pull them on, and then sat down on a convenient metal box nearby, ignoring the humming machinery beneath, to pull on the boots that Tony handed over next.

"Bright red, thick grips, puncture-proof, heck, chain-saw proof, but malleable enough to climb in..." The top followed. "Blue chainmail, because actually it's not a half-bad idea, if you make it out of stuff that won't rattle and an alloy about as strong as mithril. Gloves, utility belt – "

"I'm not Batman."

"Please, Batman has even worse fashion sense than you. Full black went out of style with the nineties." Tony sniffed.

"You dyed your hair blond, you don't get to talk."

"Ouch. Okay, but stripped-down field medkit, emergency rations – I know how you burn through food, Steve, but go easy on these because even you could get fat off of them – "

"I thought you said this was gonna be a quick trip. Non-hostile," said Steve, standing up again to put the belt on.

Everything fit perfectly. Of course it did.

"Non-hostile except for applications of Murphy's Law, and let's face it, we have shit luck," said Tony, dark eyes gleaming in the low light. "Still, I can actually show you where we're going."

Lasers began powering up, and Steve hurriedly followed Tony as he moved out of the way. His guess about the two machines behind them had been correct: one slid forward now and hooked in, Tony stepping up to force clamps down – apparently, not everything in this place ran on electricity. The way the rest of the machinery continued to do its own thing, independent of any apparent direction...

Lord. He'd thought that Tony's trick with the tablet was weird enough.

"Eyes," said Tony, handing over a pair of goggles. He didn't have any for himself, Steve noted as he put them on. They made the blue light of the laser generators turn green, casting everything in a freakish glow, as the intensity reached peak and five beams of light winked into existence, bouncing off of the reflector panels and converging to a point. A bubbling pool began to spread outward – and reflected in it was a bizarrely-coloured version of an otherwise familiar courtyard.

"Seemed like a good place to start," said Tony.

Steve nodded, staring at the image. "Probably." He tilted his head. "How'd you figure out where it was?" From the way Thor and Bruce had talked about those addresses, it couldn't be easy – it should have been near-impossible, even for somebody with Tony's brain. Apparently there were calculations large enough that even supercomputers bowed down before them.

"What, Fury didn't tell you? He got our, ah, alien friend to tell him. It's in the SHIELD database." And Tony had about as much respect for SHIELD's cybersecurity as he had for the Volvo. "Beautiful location, actually... it's weird, dimensionally speaking – it shares 3D space with us, how cool is that? It's outside the observable universe, and the way it's all connected, good god, honestly, I don't know if I could've done it without Foster doing the groundwork. I would like to have sex with Foster's brain. We would have beautiful, beautiful ideas together."

"Tony!" Steve winced, honestly shocked – Tony didn't usually get that crass until he was trying to be shocking, at least not in Steve's presence, but there was nothing troll-ish in the dreamy look that Tony had been wearing when he'd said that. Was it the effect of being made younger by twenty years, or was it some other side-effect of being wired up like a computer? Steve sighed. "You know, you could just come work with her."

"Maybe when we're done here," Tony said, the enthusiasm gone from his voice like it had never existed. Steve refused to feel bad about that. Really, he did.

The frantic hum of machinery changed again; the beams thinned, and the window in the air collapsed back into nothing as they powered down and Tony stepped forward to release the clamps. The other apparatus – it had to be the one that would make a portal – was already rotating forward. "Don't need goggles for this one," said Tony, giving a grunt as he pushed away the one and pulled the other into place. The hum began cycling up again.

"Why's it so much bigger?" Steve asked, peeling off the goggles and tossing them to the side. For all that he'd done this before... he was not a fan of having lasers shot at him, and having five instead of just one didn't make it any better. He at least wanted to know why there were five.

"Like I said, Maklu's in a weird location – it takes a lot of power to get there," Tony said, stepping forward. Steve joined him, suppressing a swallow. "I guess you could call it the furthest point in the marble store – actually, I'm not sure it's not right in the centre, but it starts looking like a fractal, so, distance – I haven't had time to run enough tests, though. Ready?"

He had no idea what a fractal was. "When you are."

"Here we go," said Tony, and blue light washed the world away.