A/N: "Double Deuce" was supposed to be a one-off, as far as crossovers go. But a lot of folks asked very nicely for a sequel, and I'm not immune to flattery... It's not really necessary to have read that story to get this one, although it can't hurt (and I would be happy if you did).

It's inevitable, in my view, that the Guardians and the Avengers will eventually cross paths; the announcement and timing of Guardians 2 and Avengers: Infinity War practically tells us as much. Mashing them up is practically a sacred duty for MCU writers! (I am, of course, steeling myself for a major Jossing on each and every point made herein.)

Many thanks to Kylen for the short-notice beta! And finally, this story is for my friend JRBarton, who knows something of the rules of hospitality.

Whistle Stop

By Alpha Flyer

Clint is asleep on the couch when the spaceship lands on the Tower's new helipad.

In his defence, it had been a really long day; the rest of the team has gone off to bed, to take a bath, or whatever, and the only reason he's still in the common room is because he'd had to restring his bow. Not having his weapon ready is not an option, especially now that he's surrounded by all these super-powered types. He'd figured he might as well fix it in front of the TV, watching someone else chase evil things for a change.

The job done, he'd dozed off just as the zombie apocalypse was picking up steam; JARVIS must have obligingly turned down the lights when he heard him start to snore. So now the room is dark, except for the flickering screen; by contrast the view of the lit helipad, when Clint's internal alarm goes off, is excellent.

Trespassers, of course, are par for the course when you live in Avengers Tower; that big "A" at the top is basically an embossed invitation for every fan boy, Murdoch-inspired hacker, paparazzo and End-Of-The-World preacher in the tri-state area. Three, four whackos a day are the norm; the occasional small horde is not uncommon.

But they don't normally get up this high. JARVIS, or Happy's goon squad, usually deal with the whack jobs well before they get past the lobby. This guy - and it's always a guy, isn't it; women may throw panties at Steve or Thor, but they're way too sensible to actually break in – and his conveyance somehow made it past the external defense system, right to the Avengers' inner sanctum.

Now, the presence of an intruder in and of itself isn't cause for panic, of course – hey, Hawkeye here? But factor in the fact that the outline of that ship outside practically screams spacecraft, and the guy's skin is bright blue? Worth getting off the couch for.

With any luck, the would-be trespasser hasn't seen him yet.

Sure enough, Blue Dude slides open the glass door and steps through like he owns the place. He's tall, bald except for some kind of metallic Mohawk in the middle of his skull, and wearing a flapping red-brown coat. Subtlety is obviously not his shtick.

Clint unfurls his legs from movie-watching position, slides off the couch and gets into a crouch, bow drawn.

"Hold it right here, buddy," he says as he stands up, hoping that JARVIS will pick up on his tone and round up some back-up, just in case. Why the general alarm has not sounded as of yet is something Stark will need to figure out later.

The alien has the good grace to be a bit startled. But his look of surprise immediately dissolves into an insolent grin, with some truly spectacular metal teeth thrown in for dramatic effect.

"Well, howdy," Blue says, in surprisingly colloquial English, and apparently un-bothered by the arrow pointing at his face. He points at it with a grease-stained finger, though. "Nice welcome. You Terrans sure are a suspicious lot."

His voice is like a cross between sandpaper and too many smokes – alien vocal chords, for sure, but where does that Rocky Mountain twang come from? The fuck?

Well, however far this one's travelled and wherever he learned to speak English, the rules of hospitality don't apply to people who weren't invited. Especially aliens; Clint has had enough of those to last him a lifetime. The temptation to just let fly is strong.

Unfortunately, if Fury has drilled one thing into his assets, it's that you can't just kill anyone who walks into your home. ("Think of the paperwork, Barton!") Plus, the guy may be the beginning of another invasion, so intel gathering is a priority.

"Who are you, and what the fuck do you want?"

The intruder bares his fangs even wider, and man, he should really consider switching dentists. Of course, he could be the Brad Pitt of blue aliens; better to keep an open mind here. What he doesn't do though is answer.

Blue Dude's gaze wanders around the room at leisure, like he hasn't got an arrow sticking practically in his craw, eyes widening at some of the pretty things Pepper likes to scatter around to keep the place from turning it into a man cave. His face turns into a frown. If he's looking for something specific, it's obviously not here. (Well, the building has ninety-three floors, so what are the odds?)

Finally, after a leisurely three-sixty scan of the premises, he deigns to respond.

"Yondu Udonta's the name, ravaging's the game."

"Ravaging?" What kind of an intro is that? Clint is prepared to give the guy points for honesty, but ... "Fair warning: We don't tolerate that sort of shit around here."

Udonta seems offended.

"Ravaging is an honest profession, no reason to be nasty." He glares meaningfully at Clint's bow. "Now be nice, or be dead. I've got men in orbit."

Yeah, well, and Clint has a Hulk three floors down. Assuming JARVIS is on the job and wakes him up.

"Bring 'em on, buddy. Although it may be easier on both of us if you'd just beam back up and go about your way."

"Not till I get what I came for."

Hands still in the air, Udonta shrugs his coat back a little as he speaks. It's a duster, like Fury's, except the leather looks like it's been dragged through an asteroid belt or two.

Time to up the threat level.

"Whoa, no more moves here, buddy. How be you tell me what you 'came for', or this here arrow will go right through your eye socket. And be a bit more specific than 'ravaging."

At least Clint thinks he's aiming at the guy's eye socket – how can you really tell, with aliens? But even if it isn't, an arrow in the head is bound to slow him down.

"No need to get worked up, boy," Udonta rasps out. "I'm here to help you. What I'm looking for is so much trouble, I expect you'll pay me to take it away."

Clint has heard versions of that line before. (Also, boy?) But before he can say anything, someone screams in the movie that, frankly, he'd forgotten about. Udonta looks at the screen and frowns.

"Hey," he says, pointing. "That guy on the monitor. Is that you? Hell of a mess you got yourself into there, boy. Flamethrowers? Reminds me of that time on Olara Prime, when Quill and I …"

Clint doesn't bother looking up. He's seen the movie three times, and knows an attempt at distraction when one is thrown his way.

"Actor dude, about to do the Noble Sacrifice thing. Which isn't my shtick at all, just in case you're wondering. I deal with shit before it gets out of hand. Speaking of which, I'm still waiting for an answer."

What the hell is taking everyone else this long? Clint allows himself a split second to look for the blinking light in the corner that normally indicates the presence of the ever-vigilant JARVIS.

Shit. No light.

And … yeah. Distraction.

The blue alien has started whistling, just as Clint's eyes return to his face. It's an odd, high-pitched, undulating sound, and …

Double shit.

Something whooshes out from under the guy's duster, and next thing Clint knows, there's an arrow pointing at his throat. From about a foot away. Just … hanging there, in the air.

All of a sudden, what had been a pleasingly one-sided scenario, with Clint in the driver's seat, has turned into a kind of Mexican standoff. And he doesn't even want to think about the technical implications of that hovering arrow.

"You seem to appreciate arrows, boy," the alien says with a baring of the fangs that could be called a smile only with a serious stretch of the imagination. "So whyn't you have a real close look at mine, and then tell me where you're keeping the Infinity Stone."

Infinity Stone? Getting somewhere, if not very far.

"Haven't the foggiest idea what you're talking about."

"Bullshit," Udonta snarls, and suddenly it's like the floodgates of conversation were yanked wide open. "We picked up the reports, on one of those frequencies Quill always listens to. You had one of them, right here on this backwater of a planet. Used it to open a portal to Thanos. Damn fool thing to do, that. Be doing you a favour, taking the stone off your hands."

Thanos? Doesn't sound familiar. But… Portal? Clint's mind starts whirring. Is the guy talking about the tesseract? Maybe Thanos is the place the Chitauri came from?

Udonta isn't done.

"That portal was right on top of this here tower. Now, talk to me, boy. We're not gonna hurt each other, are we?"

"That depends," Clint shoots back, swallowing down thoughts about the portal he himself had helped Loki construct. "I can fire my arrow off before yours can touch my throat. And as soon as you're no longer around to call the shots, I bet you that gadget of yours will make like a chopstick and drop on the floor."

Blue Dude is not impressed.

"No one's that fast."

The alien chuckle sounds like pebbles in a blender, but it's not lost on Clint that Udonta is questioning his speed, rather than claiming tactical superiority for his own weapon.

Chances are, he can neutralize the guy.

Of course, death may be a two-way street if the timing doesn't work out. Less than ideal, but acceptable in a pinch – given there are aliens involved, and all the red in Clint's ledger from the last time.

"Yeah? Try me."

Score one for intel gathering, though. Clint decides to poke at the man some more. Maybe insulting his weapon will shake something loose?

"So what's so special about that thing of yours, anyway? Looks like a cheap party trick."

It works. Udonta gets indignant.

"This here beauty is a Yaka arrow, from Centauri-IV. Never seen one of them before, have you, boy?"

Clint can't really say that he has, but he does take the question as an invitation to take a closer look.

His own arrow is still firmly pointed at his target, of course, and will remain there for the foreseeable future. Udonta seems to know it, too, and isn't moving. The hovering arrow does though, just a little bit, keeping the same distance from Clint's face. Interesting.

It doesn't have any discernible fletching, and is much shorter and thinner than anything in Clint's own quiver. The point is finer, too - not to mention that whole hovering routine, which is just … (Stark or Banner should be here. Maybe they could make one?) Specs. Need specs.

"Guess you don't have to worry about flight stabilization when gravity's not an issue, huh? How'd you fix that, anyway?"

"Anti-grav alloy, forged inside a neutron star," Blue Guy says. "Very rare. Responds to sonar impulses."

There's a little pride in Udonta's voice now. He gives another little whistle, and that goddamn arrow makes an honest-to-goodness fucking loop around the roombefore settling back down in the vicinity of Clint's larynx.

"Oh, come on."

Now Clint actually is offended, and it's not because he just blew a perfectly good chance to kill the guy and be able to get back to his movie.

"You whistle and it does tricks? Where the fuck is the art in that?"

Udonta's eyes narrow.

"The art is in the whistlin', boy."

"Bullshit. Anyone can whistle. Art is flying an arrow true, with a combination of eyesight, training, draw strength, training, mathematics and training."

Still. That circular flight was … cool.

Clint whistles a couple of bars of Dixie, just to see if anything happens. The arrow doesn't move, just keeps hanging there. Probably just as well - maybe a civil war tune wasn't the smartest choice. He tries A Space Oddity. The arrow wobbles a little, but that's it.

"You need to be Centaurian to get the frequencies right," Udonta explains smugly. "You Terrans can't do it. Quill tried it once, when my crew was gonna eat him. Never could make it work. Only way he can make music is with that stupid machine of his."

There's a lot in that statement to mine for intel - like this Quill, whoever he is, must be from Earth. (And why does that name sound so familiar?) But one thing sticks out.

"Your crew tried to eat a guy? That's … that's disgusting."

"They never tasted Terran before," Udonta shrugs, like that explains it.

"Terran?" What the fuck? Seriously. "Why don't you have 'em try Chinese?"

Well, no point getting worked up about alien eating habits, because here the two of them are, hardly any further ahead, respective arrows still pointing at each other's respective throats. He is just trying to figure out his next move, when Udonta nods towards Clint's own arrow. He, too, seems intrigued.

"I've seen a lot of weapons in my day. Never seen a thing like this, though, except in a cave painting from Deneb I once … had cause to transport on my ship. Just what makes you think that stick toy of yours is as good as my Yaka arrow, boy?"

Gotcha.

"Send yours around the room again, and I'll show you."

Udonta frowns for a second, and breaks into a grin that shows off his horrifying dental work. He gives off a long, reedy whistle that sounds like there's a Captain On The Bridge. The thing does a loop away from Clint's throat towards one of those sculptures of Pepper's, a long, spindly bronze figure by some Italian dude that look like a failed experiment in human cloning. The arrow moves up and down as it goes - a feature to tell Stark about.

First things first, though.

With a smooth, spare motion Clint swings the bow away from Udonta's face and lets fly, hitting the vaunted Yaka thing in mid-air; sure enough, it clatters onto the floor. Clint's own arrow ricochets past the sculpture and embeds itself in the wall. (No point in pissing Pepper off by scratching her art; holes in the wall she's used to.)

"You were saying?" Clint nocks his second arrow and points it back at Udonta's throat. "And don't even think about pursing those lips of yours again, or you'll be eating a nice Terran arrow sandwich."

Udonta doesn't seem particularly perturbed – but he doesn't make like whistling, either. In fact, he finally seems a little impressed.

"That's some fancy shootin'," he says. "Nice speed on the reload, too. Maybe there's hope in the archery business for you yet, boy. Even if you can't whistle worth a damn."

And just like that, Udonta seems to have decided that they're friends. He flops down on the couch and points at Clint's beer.

"You got something to drink, boy?"

Clint considers for a moment. The guy does seem more interesting than deadly, all things considered, and don't the rules of hospitality dictate that you can't kill people you're having a beer with?

Plus, arrows.

No need to be naïve, though. With his bow still trained on Udonta, Clint walks over to the Yaka arrow that's currently immobile on the floor. He steps on one end of it first, then lifts and slides the Italian thing over the other. (Fuck, that thing is heavy, despite being so spindly.) me that.

Clint slings his bow over his shoulder and pads over to the bar, gets two fresh cans of Smithwicks' out of the fridge and tosses one to Udonta, who has no problem figuring out what to do with the tab. Some things, it seems, are universal. The alien puts his boots on the glass coffee table, right among Clint's tools, and points at the bow with his can.

"You work that thing by hand, and you try to tell me there's no art in me using my lips?"

The ensuing discussion is one of the more interesting ones Clint can recall. They actually agree that in principle, adjusting to wind conditions is really not that different from having to consider different gravity fields, when it comes to targeting. There's a bit of an argument whether multiple arrowheads are a better option than whistling the same projectile through multiple targets, but a second can of beer smoothes things over nicely. Basically, when it comes to archery, it's all in the equipment and what you're used to.

Clint finds it rather refreshing to talk to a fellow aficionado. Stark makes nice, tricksy arrowheads, but he always hands them over with condescending comments, like, "Now that stone-age relic of yours can act like a real weapon, Barton!" And Nat - well, she clearly appreciates what he can do with a bow, but Clint suspects she's been secretly scratching her head about his choice of weapon since he brought her in with it, way back in Tbilisi.

But, enough fan-boying. Now that they're buddies and Pepper's stuff seems safe for the moment, maybe Udonta will tell him why he's really here?

"So, what exactly is an Infinity Gem? And why should we be so eager to give you the one you think we have?"

There follows a story about six relics from the Dawn of Time: A stone whose power can melt planets ("There's this place called Morag, no more than a slag heap now…). A liquid crystal that grants enormous power, when absorbed by one willing to deploy its force. One gem that opens holes into space; another that can bend and shape minds.

It all sounds totally hokey, of course, but for the bits that are… unsettlingly familiar.

"And, like I said," Udonta continues, "based on what we've seen, the space gem is right here. I know a guy who'll pay good money for it – he wants to rebuild his collection. He'll keep it safe, because believe me, you don't want Thanos to come looking for it. That dude is trouble, squared. Ask Quill's girlfriend."

Thanos, again - a man then, not a place. And who's that Quill guy Udonta keeps mentioning as if Clint should know him, just because they're both 'Terran'? (As in, oh you're from the States? You must know my friend Bob.) Well, at least Clint has an answer on the jewel front.

He drains his beer, swallowing a few other things down before he speaks.

"That space gem. Square and blue? Yeah, it was here. And yes, it was a whole shitload of trouble. Almost destroyed this city. Friend of mine, Thor - you may know him, he's from outer space too - took it away, to Asgard. What exactly his people did with it I don't know, but it's no longer on Earth. Sorry, buddy."

Udonta stares at Clint long and hard, like he's administering a lie detector test, and utters an alien curse. Clint only understands the word 'Quill,' so maybe it was him who'd set Udonta on his wild goose chase? Sounds like an odd relationship they're having.

Clint wants to say something sympathetic (space is a long way to come from to find something and turn up snake eyes) but Udonta is already stomping off in the direction of the balcony.

Clint is tempted. So fucking tempted. But it doesn't seem right, plus you probably do need to be from Centauri to make a Yaka arrow work. He points towards the sculpture with his chin.

"Hey! Forgetting something?"

Udonta pivots around, and glares at Clint in what can only loosely be described as gratitude. He lifts up the sculpture with one hand – shit, does everyone around here have some kind of super strength? - picks up the arrow and slides it back into his belt. Then, almost as an afterthought, he sticks the whole thing under his arm and heads out with it into the night.

Clint thinks briefly about stopping him, but don't the rules of hospitality allow guests to leave with a gift? Besides, the thing was kind of ugly, and Pepper will probably like the opportunity to buy something new.

Moments later, there's an odd sound and a bit of a light show, and Udonta's ship takes off from the landing pad.

Clint is still replaying the conversation in his head when Tony Stark bursts into the room, in full Ironman regalia. Hard on his heels is Natasha, Glock in hand, her hair looking like she's just crawled out of bed. (It's a good look - one of Clint's favourites.)

Stark is indignant.

"Barton. What was that thing that just took off from my balcony? Why wasn't I notified? JARVIS?"

And with that, JARVIS blinks back on, sounding a little confused and a lot apologetic.

"Sir, I'm afraid I seem to have been asleep. Did anything happen?"

Natasha takes one look at Clint, obviously determines that he's fine, and sheathes her metaphorical claws.

"Maybe JARVIS was knocked out by that same technology that got you in Colorado in December? You remember, when we met Peter Quill?"

There's that name again – so that's why it sounded familiar: The space traveller with the Walkman, who'd helped Stark and Natasha in a bar fight. Or caused it, or something - Clint is a bit hazy on the details, since he'd only heard about it afterwards.

Besides, he is still digesting what Udonta had said.

Given that he is surrounded by people with multiple PhDs, the ex-carnie with the over-developed biceps is rarely credited with having a functioning intellect. Indeed, he rarely admits to having one - there were times when being the smartest person in the room had brought Clint a world of hurt.

But the truth is, Hawkeye can think with the best of them - and he is thinking now, hearing Udonta's voice in his ears: A gem that can bend and shape minds.

A blue glow, infused with the cold of space and time; a single touch, and Clint Barton ... wasn't. What could a power like that do over time?

First, it would want to be forgotten.

"Barton? You with us?"

Stark still sounds like it's somehow Clint's fault that aliens are able to knock out his vaunted AI at will, twice in a row. (Maybe he should work on that?)

"Barton! You okay?"

Rogers has arrived in sweats and a t-shirt, but carrying his shield, ready for war. Everyone is looking at Clint now, waiting for answers.

It's been an interesting evening, even fun, in some way. And under other circumstances Clint might have enjoyed having one over on his high-powered teammates, and be spinning them a yarn about the blue alien whose arrival they'd all slept through.

But there is nothing funny about the truth. Not with the blue-rimed memory of Loki's orders and the flames of the fall of S.H.I.E.L.D. still burning in his mind's eye.

"Yeah. I'm fine."

That's not a lie, exactly, but neither is it entirely true. Clint turns to Natasha and Steve, unable and unwilling to hide the chill in his voice.

"Does anyone know where Loki's scepter is?"