Chapter Text
It all starts by sheer coincidence.
Tony is trying to hide from a kill squad that, somehow, has managed to find him –it isn't really like that, he knows, those fuckers had managed to track the reactor’s energy signature, but if he thinks about it he will have to think about searching another way to not die without the reactor, or going back to a car battery, and both are big no-no’s on his book, so it’s better not to think about them for now. Really. So he goes underground, because not even Chitauri technology or human technology enhanced by Loki’s magic or whatfuckingever it is can track such a little energy two floors into the earth.
He has been alone for two months since everything started, since Loki opened that hole on the sky of New York and won the battle. The Avengers had tried to keep fighting, to not let it just happen, but little by little they became apart. Thor was the first to go, knowing that he could win some time for his teammates if he caught Loki’s attention by using his obsession. All the others made it, but Thor never came back. Tony still doesn't know whether the bigger than life Asgardian god has died or is currently in chains somewhere while Loki laughs at him. After that it was Bruce, trying again to save the others from a tight spot and disappearing – and Tony wants to believe what people whisper sometimes, about a big green beast running wild in the mountains. Maybe it's true. Maybe Hulk decided it was safer to never be Banner again and that's the only reason they never came back. He wants to believe it so bad that sometimes he wakes up at night, sure that he has just listened a roar in the distance instead of his own heartbeat drumming in his ears.
After Bruce, everything happened really fast. Natasha looked at them, thin and weary and exhausted from running, and decided that winning was more important that their little group and went her own way in the dead of the night. Tony can't find it in himself to hate her, not when her eyes had been getting more and more full of ice with every day, not when he fell asleep every night hearing her sharpening her knifes. He thinks he understands it now, that urge to win, to have some kind of vengeance no matter what. He understands it now that he has to stop himself from thinking about getting rid of the reactor because it scares him shitless. But if he thinks about it too much he will do it, even if he can't draw a full breath ever again. He knows that his brain has more value that his fighting skills and it would be better to be safe in just one place and creating, making something even without breath, instead of running around like a scared kitten and nothing more. The problem was that they woke up and Natasha and her things were gone. Clint didn't last even a day, saying that he could still find her if he was fast, that he could still help if he was with her. He appeared so broken, his eyes so shiny, that Tony just nodded and grabbed Steve's wrist to stop him of trying to hold Clint back by force. It said a lot that Steve just hung his head and looked at the ground instead of shaking Tony off and keep trying.
Steve was the last one, but this time it was Tony who decided to stay behind, buying time. Because he couldn't let Steve fall, after all. Steve was everything that was good in this world, he had to keep going, had to keep thinking that it was possible and fighting. So Tony stayed in the subway station, hearing the howls of those things that looked like the Chitauri’s version of a dog, only three times bigger and a million times meaner, and after searching for the last of his supplies in his backpack, made a couple of things go boom.
Miraculously, he survived, waking up some hours later in a bubble of air between the rubble. He had some painful scraps made by chips of cement flying around, and was pretty sure that it wasn't actually that silent around him, it was just his ears calling dead time for a while. After almost a day he managed to get out of there, using a hole in the ceiling made after most part of the station collapsed on itself. But there was no trace of Steve. ‘As it should be’ thought Tony later, when his own thoughts didn't echo inside his head until he felt he was going to bleed from his ears.
But even if he had done the right thing, it didn't change the fact that it was fucking difficult to keep going utterly alone. He had let his beard grow, and his hair probably looked like a really ugly bird nest at this point. Food was difficult to come by after Loki instated a food-check system. You didn't work, weren't registered in the census, had glared at somebody with power? Good luck then trying not to starve. Not even all those deaths, all that people dying while trying to protect themselves and how they lived, had allowed for bigger rations of food for those who still breathed. And being on the run, always hiding, wasn't exactly a plus.
Tony was on the search of one of the secrets SHIELD bases when he heard the rumor that there was a Chitauri ship over the trees. He hadn't been able to see it yet, but neither did he need to. He may have been on the run with just a pile of scraps in a backpack, but he still knew his technology, and that low purr belonged to a medium size ship, with probably around 10-15 soldiers, both human and Chitauri. So he started running, trying to find that damned secret door to the underground base that he remembered having read about once upon a time, when his biggest concern was how to make Fury's eye twitch.
And there he is now, crouched in the darkness, breathing with his mouth open to try and not make a sound while the Chitauri “talk” between them four rooms down the hall in those chirping sounds that make his teeth hurt, and wondering how many of them can he take down before his blood is the one pooling in the ground. Six, he thinks. Ten of them if he is lucky and they carry more explosives that can detonate with the first (and only) blast he can make.
Or, more probably, zero, he thinks with dread when, without warning, the lights start humming and come on with a blink. Fuck, that is the reason they haven't started to search the base yet. It looks like the rest of the unit has gone to find and activate the generators. Tony gritts his teeth, tensing and getting ready to jump over the first Chitauri that goes into the room. The room itself looks like a storage room, with containers made out of metal. Sadly, most of them aren't tall enough to be used as coverage to avoid being seen if they take more than just a look.
His thoughts scatter when the sound of heavy feet stomping echoes on the hall. A door slamms open somewhere, closely followed by things falling to the ground, broken. Yes, it definitely isn't going to be a game of hide and seek that much longer. Another door, more noises. Are they going first to opposite rooms, instead of doing one side first and then the other? He can't tell, not with all the echoes resounding over the metal walls. The steps come closer. He crouches low, ready to jump. A chirping sound. Metal against metal. Something scraping on the other side of the door.
Tony doesn't give himself time to think. He jumps even before the door opens, just in time to knock over the first one. It hits its head against the door frame and stays down, and Tony jumps back, using the wall as a shield from the energy blasts. He hides behind one of the crates, ready to try his luck one more time and see if he can get one more by surprise. The room isn't so big that they will risk to jump all in, not when his weapons aren't designed to close range as it is.
As if reading his thoughts, just two of them go in, looking around with their arms ready. They ignore their fallen teammate and go in different directions. Tony closes his eyes for a second, trying to find peace inside himself, or, or something, he doesn't know. It just doesn't look like he is going to get out of there after all. He twists into a ball, and as soon as the closer Chitauri is into range, he jumps to his feet, knocking the spear with his elbow and pouncing forward. The spear shoots and, judging by the screech and sound of broken glass against the ground behind him, it manages to hit the other Chitauri, but Tony is too busy trying to grab hold of the Chitauri armour and make some damage.
It trashes, managing to dislodge Tony, but not before he digs his knees on its gut (a lucky hit). Tony gets up, ignoring the sting on his hands after stopping his fall with them and jumps over the back of the Chitauri before it recovers and straightens. He crosses his arm over its neck and tilts his body backwards, trying to cut its air supply with his weight. Do they even need air to live? Tony remembers that in New York they had fought with some kind of mask at the start, but then, they were aliens, so who knew. Maybe doctor Foster. As it was, he is ready to try everything he can think of instead of just kneeling and diying like a good little slave.
He breathes hard, grunting when the Chitauri tries to crush him against the wall, crashing against it over and over. The chocking hold doesn't seem to be working, specially when the hard metal wall against his back makes it impossible to use his weight. He still has strength in his arms, even after the lack of food and the running, but not nearly enough to do it with just his muscles. His lungs hurt and he kicks his legs, trying to hold on the body under him. There is a sound of broken glass being stepped on on the other side of the room, and where are the others? Have they divided before starting to search the rooms? Is Tony about to die with a nice energy blast mark on his head or something? He cringes, because of both the pain when the Chitauri cuts his arm open with its nails and the thought of never seeing the blast coming. Just the lights going out and goodbye Tony Stark, you tried hard but it wasn't enough.
Then suddenly the Chitauri makes a strange twist, something that should have broken its hip had it been a human. One second Tony is clinging to its back, and the next his head connects with one of the crates.
It doesn't go as in the movies, where everything just goes black. His whole body falls slack and hefeels as if he is floating, not feeling the drop against the ground. There isn't pain, or sounds, and he can swear his eyes are open but things come in flashes. The Chitauri turning around to look at him, his ugly skull-like face distorting even more in some kind of grimace. The Chitauri gone, and a vibration at his left while he looks at the ceiling, unable to even think, with his head feeling like it is full of cotton. Cold filtering into his jacket, caressing his neck. Something black and blurred moving somewhere at his left. His backpack poking at his back, and one of his shoes half dislodged in his struggle. The lights overhead blinking in that way neon light tended to fuck with you. The black thing coming closer, peering at him, so, so tall, Tony wonders if he can screw better the light so it stops blinking. It doesn't let him think.
The black thing moves, its lips moves, and some part deep in Tony's brain thinks Ah, I should probably put attention into that. That looks important. But then he blinks and the thought disappears. He doesn't try to open his eyes again. He is tired, after all, and kind of sleepy, so it is okay. He will just let his mind go for a while. It is probably okay.
Chapter Text
When everything comes back, it does with a vengeance. There's a pounding in his temple, his face and neck feels sticky and he's freezing all over. Tony groans, swearing to never, ever again drink whatever he was drinking before crashing on the ground.
What finally makes him open his eyes, after some minutes whimpering and twisting around, trying to get out of the draft, is the sound of leather crinkling. Tony jumps, sitting, and then gasps and grabs his head with both hands, fighting the nausea that is trying to put him on the floor one more time. He hisses, moving away his right hand when the pain shots inside his head. Tony blinks, looks down at his hand, now dirty with clotted blood, and then the other one when a secondary pain starts to pulse with every beat when he moves his arm. There's a bandage on it, and judging by the feel some suture points under it, on the inner side.
Everything rushes back. Loki, New York, the Chitauri, running from them, hiding in a SHIELD's base, the fight.
The panic jams his throat, and before he knows he is moving back until his back crash with one of those damn crates, knees bent almost against his chest, trying to protect himself. But no one jumps him, there are no kicks or punches. When he finally gathers courage enough to open his eyes more than a gap, he sees just a man, sitting on one of the little crates, looking back at him, expressionless.
His thoughts run at the speed of light, trying to understand. He is in the same storage room where he fought the Chitauri, with the metal walls and the crates all around. There is a scorch mark in the opposite wall, surely where the energy blast that Tony managed to divert hit, and some kind of capsule next to it, its glass shattered on the ground. A light fog comes out of it, and as he shudders, Tony thinks that's probably where the cold is coming from.
There are some dark stains in the wall and ground, too. Dry and coagulated, as well as deep scratches on the metal floor, and if he knows something it is that sure as hell that looks like somebody started a fight – one a lot more vigorous than his – and Chitauri blood.
The leather crinkles again when the man moves minutely, and Tony almost jumps in the air, concentrating again on him. He's taller than Tony, a lot more bulky and dressed as if he just came out of some very special club that offers whips and collars with your drink. The first thing that makes him think that something doesn't add up is that he looks way too pale, with bags under his eyes and his hair long and greasy. It isn't exactly the look that the spoiled soldiers and mercenaries who swore loyalty to Loki have, nor the one that diva wants them to have – surprisingly, what Tony has seen until now tells him that Loki is a crazy son of bitch, but one that is trying very hard to look like a benevolent ruler while killing everyone who doesn't kneel fast enough. So no, the “I don't know what a shower is” is not the look of his men.
The second thing that calls his attention, and if that isn't a signal that he suffers from at least a mild concussion, then nothing will ever be, is that his left arm is made of metal. Like, very cool, I want that and I wouldn't mind to rut against it metal. It's scratched hell and back, the metal dirty instead of shiny, as it probably should be, and Tony can't be sure from this far, but if those are hydraulic gears to displace resistance and strength instead of just fashion marks, then they are damaged, slightly misshaped and making the man unable to extend his arm, stuck in a 90 degrees position, partially over his lap.
“Mission parameters?” the man asks, but it doesn't sound as a question, too flat, the sound rusty as if he isn't used to talk. There's a light accent there, something that blurs the vocals but isn't recognizable.
“What?” is the only think Tony manages to say. Because he's pretty sure, now that his head is getting clearer, that the kill squad which managed to find him was compounded just with Chitauri, what with all the chirping around, and he doesn't think they are strange enough as to bring somebody here to interrogate him or whatever instead of take him to Loki.
The man doesn't ask again, looking at him with dull blue eyes. But neither does he stop him when Tony, slowly and using the crate at his back as a crutch, stands up. He has a moment of panic when the dizziness almost makes him fall again, but it passes. There are no sounds from outside the room, not even the generator that has to be somewhere. No steps, no chirping. Nothing. It looks... safe.
Tony turns his attention again to his injured arm. “Did you stitch me up?” he wonders, rotating hand and arm to see what his range of movement is. He isn't sure if he should be so calm with this person, he isn't sure he is, even. Maybe it's just that, after running for so long, anything that doesn't try to kill him at first sight is welcome at this point. “Handlers safety must be assured at all times” the man says, and Tony arch an eyebrow, pocking carefully the dressing.
“So what” he says, ignoring the handler part. This is a SHIELD base after all. Maybe this dude with the cool arm is a SHIELD agent in hiding. “You take care of my arm but ignore the head wound? Really? What was I, bleeding out?”
There's no answer, and when Tony raises his eyes he can't stop from fidgeting a little with the strange intense yet hollow way the man is looking at him. Well, it looks like a yes to his question. So Metal Arm helps him but just the indispensable. That's, okay, he can work with that.
“And the Chitauri?” he says, looking around. There are more splotches of blood in the corner behind Metal Arm, but he can't see any body. It doesn't say much, because even if the crates won't hide anyone very long, it is possible that the bodies of his attackers are behind one, out of sight until he comes closer. “You know” Tony adds in front of the slow blinking from Metal Arm, “gray ugly dudes, spears, all that.”
Metal Arm lowers his eyes, looking like he is mulling over that phrase and his answer to it. “The perimeter is clear” he says at last. “Eight intruders down in this level, six more between here and storage room F11. Weapons not recognized.” At that, the slight air of bafflement that Metal Arm has around himself changes to... anger? Disappointment? Acceptance? It comes and goes so fast that Tony isn't sure – he has never been that in touch with emotions as to read them that fast in strangers – and after that Metal Arm looks again like a big living doll, raising his eyes towards Tony.
Tony himself is looking at Metal Arm with his eyes open wide, he can tell by the way the dried blood of the side of his face is pulling at his skin. “Are you saying you toke them down? All of them? Full squad?” he gapes, unable to wrap his mind around it. He knows how strong those fuckers are, all New York knows firsthand. But Metal Arm just keep looking at him, closing and opening his left hand in his lap.
“Handlers safety must be assured at all times” he repeats. “The arm suffered damage” adds, almost as a second thought. Well, yes, thinks Tony, taking a step closer. That would explain why the metal isn't as shiny as it should, and the bending of its parts. This crazy fucker must have stopped the energy blasts using the arm as shield, and seeing how he moves his hand, without any visible lag, sends a shiver down Tony's spine. That beautiful thing must be connected to his nervous system to move like that, and just the procedure to do it makes his stomach clench. He really, really expects there is some kind of protection against electrical shocks in that arm, because if not it must have been a really painful fight.
He has so many questions. Who is Metal Arm, what is he doing here, who gave him that arm, how did he manage to put the Chitauri down, why did he do it... He has to clench this jaw to repress them all, because even if his curiosity is killing him, right now there are more important things to do. Like running for his life, for example.
“How long was I out?” Tony takes off his backpack, making sure nothing was damaged in the fight. He doesn't want to go sky high when trying to ring something because a little struggle fucked up the components. There's probably a lot he can take from this base if he can spare the time. Even if it just some canned food. But Metal Arm's answer puts ice into his veins.
“Five hours” he says. Tony raises his head, just looks at him.
“You are fucking kidding me.”
Metal Arm frowns slightly, like that is something so out of the realm of possibility as asking him to fly with a thought.
“Fuck.” Tony puts his backpack on again, looking around as if somebody is about to jump him as soon as he isn't looking everywhere at the same time. “Fuck. Fuck, fuck, fuck. I have to get out of here before those things send another squad to see what happened.” He is already planning what to do. Before going, he has to make a stop to the Chitauri ship and see if he can find and take whatever they used to trace the energy of the reactor. It may help him to find some way to conceal himself better.
“This is just such a fucking mess. I would have had a whole base, all of it for myself, well, and you, of course, to hide and work and fuck, but no. They had to find me just as I got in, of course. A safe place, that's the only thing I ask for. It isn't that difficult, is it?” He's rambling, cleaning what blood he can of his face with the hem of the sweater he wears under the jacket. “You better hurry too, dude, because they aren't going to send just one squad this time.”
Metal Arm stands up, his arm still stuck almost against his abdomen. “There is another base 80 kilometers from here. We should be there in under an hour with one of the jeeps” he says, and that stops Tony, who looks at him with arched brows.
“You coming?” he can't help to ask.
Metal Arm stops, blinks once, as if taking by surprise by that. “Protocol establish to stay with the handler until receiving mission parameters” he recites, and whoa, maybe Tony came across a SHIELD agent with some screws lose. He can't really think Tony is an agent too, right? Much less his boss, not after how Tony acts. Then the man tilts a little his head, as if considering something else. “A distraction could be provided.”
It takes a second until Tony gets it. “Oh yes, what about no. I'm not leaving you here to be gutted so I can run for the hills. I have to go out for a second, grab something of their ship. Do you know where everything here is?” Metal Arm nods, looking more comfortable when he can get by without words. “Good, grab whatever you think we may need from here and will fit in the car and prepare that jeep. We have to be fast.”
He doesn't look back to see if Metal Arm obeys, going out the door, but the sound of metal against metal tells him that he is, probably searching what is in all those crates and what could be of use.
There are more signs of a fight in the hall. Splashes of gray blood in the walls, burn marks. The body of a Chitauri at the end of the hall, with a blackened hole in his chest, tells Tony that maybe Metal Arm doesn't know what an energy spear is, but he sure as hell has learned to use it fast. Tony holds his breath, getting out of there as fast as he can, avoiding bodies and extremities.
The ship isn't far, hidden or closed. Tony says his thanks to the heavens and goes in, pretty sure there aren't nasty surprises inside, not with how certain the Chitauri must have been that they finally had him. The inside isn't as different from a Quinjet as one could think. Sure, there are more lights blinking, and it looks like the way to steer this tings is with some kind of connections to your neck (Tony crosses out the idea of steeling one of these), but the space is split up between a cockpit and the area of cargo, without any seats. The Chitauri must believe a soldier should be able to stand all the journey. Or maybe it's just that their gravity is lesser than the Earth's.
He doesn't search for weapons or anything he can take with him. With his scarce knowledge of their technology, it's more than probable that he grabs something with a beacon on it. Luckily, what they used to find him it's just a hand-device with a screen that displays the parameters of the energy you are tracking, and it's waiting next to the cockpit. That should be enough to be able to discover how to cancel the external energy output without altering the magnet in his chest.
Tony gets out of the ship and looks at the sky. There aren't any vibrations in the air, so the reinforcements aren't close. Yet. He supports himself again the ship, taking deep breaths and letting himself panic for a moment.
It has been a close call. Too close. If Metal Arm hadn't appeared just in time he would be dead, or a slave, and he isn't even sure which one would have been worse. He just needs a moment to think, a moment to swallow the fear and clear his mind. Should he trust Metal Arm? He doesn't look that much in contact with reality, but he has saved him twice, if he really was bleeding out. And what was he doing alone in that base? Did he flee after the attack on New York, while SHIELD got destroyed trying to stop the invasion? Or was he somebody left behind to take care of it instead? Should Tony worry?
At the end, though, he can't keep being alone. Metal Arm is who knows about the other base, he hasn't proved to be dangerous for Tony and he has fighting skills that could be the difference between winning or losing. So Tony will keep an eye on him for now. With that in mind, he straightens and walks back into the base, trying to find the motor pool and his new friend.
Chapter Text
When Tony finally finds the motor pool, he has to recognize he is suitably impressed. The car – a Chevrolet Suburban, not a jeep, mind you – is big, but it looks as loaded as it can stand. He whistles, coming closer to peek what is in there. The backseats and floor has three metal little crates, not very different from the storage room, a big med kit, water and what seems to be boxes full of canned food and MREs. Canadians ones at that. He can't help to laugh seeing them. It isn't as he has a lot of experience with those, but he still remembers Rhodey all grumpy because, apparently, Canada's MRE were tastier.
Tony doesn't allow himself to think about what happened to Rhodey. The last he heard from him, he was in the Middle East just before Loki's attack.
He is about to take a look to the frontal seat, but he gets sidetracked when Metal Arm enters the garage with a duffel bag that he loads into the trunk.
“Holy shit, I should have called you Terminator.”
Metal Arm has found even more leather to wear in the form of a harness around his shoulders, where he has a submachine Skorpion vz. 61 (Czechoslovakian), and two – two! – tight holsters. The left one with a SIG-Sauer P226R (a beautiful gun, stainless and reliable, a good choice) and the right one with...
“Are those Derringers? You are shitting me. You are absolutely shitting me.” Tony walks closer, squinting and feeling almost offended. Yes, they definitely are. A COP 357 Derringer and an Intratec TEC-38. “What the hell. Couldn't you find something with worse aim? Those things have more numbers to hit me than a Chitauri.” He goes for the Intratec, taking it out of the holster and examining it. It's exactly as he remembers, even if it looks like they have taken good care of it. It's an ugly and heavy piece of poor quality plastic, with two very short barrels and an unfinished trigger guard. Just two shots, powerful but almost useless unless in very close range. Exactly the same that the other Derringer, even if that one is prettier, made in chrome and with four barrels.
“What are they, your late '80 version of a cyanide tooth?” he jokes, raising his head, but the smile disappears fast from his lips. Metal Arm looks downright terrified, his blue eyes, big and lost, fixed on Tony. All the little color he had has disappeared, and his right hand trembles slightly, tense at his side. He looks like he wants to curl into himself and hide but he won't allow himself to do it.
“The– the options were limited. This base is not operative” he says in a low voice, looking only even more scared afterward and tightening his lips together. Tony has an uneasy impression it may be because Metal Arm thinks he isn't supposed to talk back at all.
“I see.” Tony moves slowly, handing back the gun. Metal Arm keeps watching him for a second, like he could turn into a snake and bite him if he moves, but finally he raises his normal hand and takes it back, holstering it. He never stops looking at Tony, and even once he is unarmed he still looks uneasy, but he seems to be trying to contain the emotions on his face.
“So, should we?” Tony changes tactics, stepping back towards the car. That seems to relax Metal Arm even further, who nods, and Tony is starting to have very bad feelings about Metal Arm. Why would he think so fast that Tony was a “handler” of his, but at the same time be so scared of him? It can't be because Tony himself. So that just leaves that Metal Arm is usually scared of his handlers, whoever they are. He was going to ask him his name, but maybe it would be a better idea to wait to being safe and established in the other base before start making questions. Specially seeing how Metal Arm reacts to some of those.
When he enters the car, riding shotgun – Tony isn't sure of how well can Metal Arm drive with the state of the prosthesis, but he isn't a better option. He is concussed, tired and hungry. And Metal Arm knows where that base is anyway, so this will be faster – he notices a little first-aid kit resting over the dashboard. “Oh, hey, thanks” he says, surprised, opening it and grabbing some gauze to clean his head wound. Metal Arm says nothing, starting the car. Tony uses the little mirror on the flipvisor, and while doing it he notices the others cars in the motor pool. They are all black Chevrolets, not the Acura MDX custom made he has came to associate with SHIELD, black with the white eagle on the sides. Actually, not even one of the Chevrolets has the emblem. Is that because this base was not operative, as Metal Arm said, or because SHIELD was trying to keep it under wraps? It's a useless curiosity, but he would have liked to be able to look around a little bit. Maybe he could have learned something about what the hell was SHIELD doing with Metal Arm.
Maybe he is obsessing a little bit with that dude. What can he say, he seems like a problem he can find an answer to, unlike everything else at the moment.
“But that really is a lot of guns” he can't help to say once he has finished with his wound. “Did you put everything you found in those holsters or are there more?”
Metal Arm just looks at him in silence, and afterward the globe box. Tony follows his eyes and opens it, and there is a Glock 19, black and pretty standard, but as well cared of as all the others.
“Is this for me?” There's no answer, so Tony is going to go with 'yes'. He puts it again in the globe box – he doesn't have a holster, and he isn't stupid enough to put it into his pants. It's his hand or nothing. “But I don't see how you need all those weapons. I mean, you have three guns, a submachine and three knives! You stopped all those Chitauris without anything”
“Four.” Before Tony has time to ask, because he is pretty sure he has seen just three (a Gerber Mk II in one of the holsters and two matching knives Gerber Yari II Tanto and the end of his back), Metal Arm moves is flesh hand from the steering wheel, driving between the trees and following the almost unmarked road just with the little mobility his metal stuck arm gives him, and in a movement to fast for Tony to follow, he draws a knife, a different knife, and pass it to him.
Tony takes it without thinking, blinking owlishly. It's a sleek thing. The handle turns into a double edged blade smoothly, and it looks sharp. There's a loop in the handle's end, and it explains why he hadn't noticed it. It's designed so just the loop peeks above the sheath, easy and fast to get out with just a finger, his size and figure perfect to keep in one hand while aiming a gun and change fast from one weapon to other. It's an urban knife. It's for stabbing when somebody gets too close. It sends a chill down Tony's spine. There is a level of coldness in this knife, worse than the military ones. This is for murder and darkness and nobody ever catching the killer.
He gives it back without any comment. Metal Arm grabs the steering wheel with his right hand again. Tony tries not to think for a while longer.
It's strange than a little knife is the one making him aware that, maybe, there's something deeply wrong with his new friend, his mechanical arm and his fear and what seems to be need of some kind of handler. If he is SHIELD, then he probably isn't that much into the sane side of the coin, and if he isn't... Tony doesn't want to think about it. It's bad enough if he is SHIELD, and honestly, he just wants something to go right for once.