Tony Stark had been improbably, mildly inexplicably, and actually asleep. In his white-walled, sparsely and squarely furnished, real bedroom. By himself. But then the air pressure changes and he is suddenly, startlingly, completely awake, as rigid in his bed as if someone's pointing a gun at him. Nobody is, but it takes him a couple seconds to process that fact. Then he works his jaw around until his ears pop, scrubs the sleep and panic from his face, and levers himself out of bed. Tony considers a night wasted if he doesn't spend any of it in the lab, and just because he'd collapsed, exhausted, into bed after an unexpected small-scale run-in with a couple Doombots doesn't mean he's given this night up for lost.

"Hey JARVIS? Why does the house have a destabilized cabin pressure? It's still attached to the Earth, yeah?"

"The foundations are firmly in place, sir. But there's been a power surge to the lab."

"Oh? Anything turn up on the video feeds?" Tony pads across the living room with its curtainless view of the beach and the sea and starts working his way down the stairs.

"No sir."

The stairs wind downward in a lazy counter-clockwise spiral. The original blueprints for the house had them run counter-clockwise, but this had changed as soon as Tony got his hands on the plans. A lot of other things had changed too—Tony had connected his workshop with a tunnel/driveway "like the bat-cave but cooler," he'd told the lead architect—but the most important were the stairs. Tony remembers reading somewhere that the staircases in old Army forts spiraled clockwise so that someone running up them had a wall behind his right arm while someone going down had ample space. Space that might be useful for, say, cocking and aiming a rifle. And while Tony hadn't been planning on battling anyone over his staircase at the time the house was built, he had felt that, as a weapons manufacturer, he should nod to the defense systems of the past. But since Tony's fortress (his lab) was at the bottom of the stairs rather than the top, he'd had them flipped around. Now, of course, that clockwise spiraling is loose enough that he can fly the Iron Man suit up and down the staircase if he needs to, and the space behind his right shoulder is great for lining up a punch.

"No change in thermals?" he asks JARVIS.

"None of the security measures have changed status, sir. And must you always question my competence?" He—Tony had stopped calling JARVIS an "it" right about the time that he first insulted Tony—sounds almost bored, and a little more British than usual.

"Forever and a day, sweetheart."

He stops just at the base of the stairs and peers through the glass walls of his lab. It's as dark as Tony had left it. The complex apparatuses he'd placed haphazardly across the benches cast complex shadows on the floor. They're lit only by the faint glow of the trophy case along the wall to the right, where Tony keeps every iteration of his suit behind (thick, heat-resistant, bulletproof) glass.

Tony lets the door to the lab scan his hand and his eye and his voice and steps through when it opens for him.

Probably the first thing he notices is the light. About half of the overhead lighting was on, just dim enough so that Tony doesn't have to squint against it. The second thing he notices is the tall, dark figure in the corner by his suits, facing him, pointing a prototype palm repulsor at his chest. The third is the chill in the room, which rolls over Tony's bare torso like icy, exploratory fingers.

"Pow," says the figure in a voice he recognizes.

"JARVIS, put everything on lockdown. Tightest you got. Code Alpha. Everything."

The figure smiles, a slow, creeping smirk that doesn't so much cross his face as ooze along it. "Anthony, do you really think your security can bat an eyelash at me?"

"It's Tony," Tony says tightly, "And I'm willing to maintain the illusion." He starts edging around the perimeter of the room towards his suits. "And speaking of, how'd you get in here anyway?"

"Magic." The figure wiggles his fingers suggestively. "I believe I used what you in Midgard call a 'glamour'?"

Tony raises an eyebrow. "Fairies use glamours, not Norse gods. Are you a fairy now, Reindeer Games?" He makes a show of eyeing the shiny gold and green tunic, the heavy leather coat. "With the way you dress, maybe. But for the record, I think it's stylish. Like you're wearing the interior of a castle or something."

Said Norse god does not appear to appreciate Tony comparing him to architecture. He flexes his fingers around the blaster and glowers. If Tony didn't make it a personal goal to be glowered at at least once a day, he might have wavered. As it is, he keeps edging towards his suits and fervently regrets wearing just boxers to bed. The suits chafe like a pumice pad on a herpes outbreak when Tony wears them without a body suit or clothes on.

For his part, Loki pivots so he faces Tony throughout his traverse across the room. He doesn't look particularly concerned that Tony is getting in range of some sort of defense against him, and Tony doesn't know whether to feel proud because of this or terrified. He settles on terrified as a feral, hungry grin twists Loki's face.

"What do you want?" Tony demands. It's one thing to meet Loki in the field of battle, out in the world where there's imminent and large-scale death and destruction going on. Because then it's Iron Man versus the God of Chaos, two forces battling each other for the sake of a multitude of lives. But Loki's in his house, in his lab, where the line blurs between Iron Man, flashy paragon of justice, and Tony, an inventor slowly approaching middle age who designs fancy glowing pacemakers and believes in things like duty and loyalty even when he looks around and sees that he doesn't—sometimes can't—offer those things to people who deserve them. He doesn't want Loki here at all, to say nothing of the fact that he'd thought Loki was busy getting a face full of Asgardian justice.

Loki brings his free hand around behind him and pulls out the glass case with Tony's first arc reactor in it. The one Pepper had given him to replace the one he'd broken to save his life. The one he keeps in his lab to remind himself that other people actually believe he's a decent person.

"This is what powers your creations, no?" Loki inquires, turning the case over in his hand. His fingers are lithe and dexterous, almost as sharp-looking as the corners of the glass.

"In case you forgot, Puck, I have a real issue with people taking my things."

Something flares in Loki, something that draws him taught and upright and a little forward, something that opens his face and Tony almost sees something there, something real, but Loki shuts himself down and whatever it is was only there for half a second and now it's hidden again.

"Oh I'm not here to steal it," Loki says. There's a crystalline crash as the case shatters in his palm and glittering shards of glass trickle to the floor. Loki palms the reactor, getting a feel for its contours. "I'm merely curious."

"Yeah? Well I'm mighty curious myself."

Tony has his back to the case of suits. He can deal with this. He still has on the bracelets for the Mark VII, which is stashed in a storage case to his right for repair. It's more banged up than he'd like and one of the repulsors doesn't work, but it'll do. But it would take a few seconds for the suit to assemble itself around him and he doubts Loki would give him that long. So instead of backing towards the cases of personalized weaponry behind him, Tony Stark moves forward. Loki watches him silently, still toying with the reactor. He strokes the cord attached to its base and tugs at the adaptor at the end. He looks regal and a little bit amused.

He looks shocked when Tony tackles him. They crash to the ground, Tony's head somewhere around Loki's midsection. Where Tony'd been expecting solid metal armor he finds something soft enough to be flesh, so he plants an elbow into what he hopes is Loki's solar plexus as he heaves himself up the god's body to grab at the reactor Loki still has clutched in his hands. The god wheezes gratifyingly, so Tony knows he's hit something. Then Loki's arms swing down from over his head and Tony feels something hard crash into the small of his back. Pain blossoms, taking root in tendrils of tingling numbness down his legs.

Shit.

Tony grasps above him and his fists tangle in dark hair. He pulls down as hard as he can, forcing Loki's head back. Then he frees his right hand and slams it into the underside of Loki's nose. He hears a crack and feels otherworldly cartilage splintering. The hands at his back loosen momentarily but are back with a vengeance as blood spouts from Loki's shattered nose. The god gurgles a roar as he flips Tony underneath him. Tony grabs for his arms and gets a foot between them, under Loki's belly. He knees up between Loki's legs with his other leg, missing his balls (unfortunately) but getting him tilted forward, and shoves mightily with his planted foot. The god goes flying, landing flat on his back on the workshop floor. The arc reactor rolls away under a table. Tony activates his bracelets and stands, shakily, with his arms out so the suit can build itself around him.

Loki raises one long arm and gestures. The busy clicks of interlocking metal stop abruptly. Tony stands stock still, half stuck in a partially-assembled suit, half pissed that Loki doesn't have the good graces to at least pass out. But the god rises fluidly, if slowly, and the blood is already drying on his face. He shakes the remnants of the prototype repulsor from his arm and flexes his fingers. He gives Tony a slow, wicked, hungry grin.

And he vanishes.

It takes Tony twenty minutes to extract himself from the half-assembled suit. When he's finally free, he leaves it standing there in his lab, a great metal chrysalis from which something bigger has emerged.