#avenger!buck

The quantum tunnel spits you out on Morag in 2014, and the first thing you notice is how quiet it is. Dead quiet. Just wind and ruins and the distant sound of waves.

"We've got forty-five minutes before the window closes," you say, checking th GPS device on your wrist. "The temple's half a klick north."

Steve adjusts his shield. "Stay sharp, we don't know what we're walking into."

Bucky's already scanning the perimeter, rifle raised. "Looks abandoned."

"It is," you confirm. "Quill still unconscious down there. We're early."

The temple is exactly where it should be—a massive structure carved into the cliff face, a fascinating alien architecture. The power stone it's placed in its pedestal, sealed in the orb, pulsing with barely contained energy.

"Okay," Steve says. "Nice and easy. We secure the stone, get back to the platform and—"

The explosion cuts him off.

You're thrown sideways, slamming into one of the temple pillars. Your ears are ringing. Through the smoke, you see them: Sakaraans, maybe a dozen of them, firing indiscriminately. They must have followed you when they saw the quantum tunnel.

"Get the stone!" Steve shouts, shield already deflecting blaster fire.

Bucky's at your side, hauling you up. "You good?"

"Yeah, go—"

Another explosion, closer this time. The temple shudders and you watch in horror as the pedestal cracks, the orb rolls free splitting open on the ston floor.

The power stone tumbles out, raw, uncontained, pulsing with enough enrgy to level a planet.

Everything slows down.

Bucky's moving toward it—he's a super soldier, he might survive the exposure—but you're closer. You're already running. You can hear him screaming your name, but you're faster. Your hands close around the stone, and the universe explodes… at least for you.

Purple lightning crawls up your arms, through your veins, behind your eyes. It's not pain, it's way too big to be pain. It's everything, all at once. Every star being born and dying, every moment that ever was or ever will be, all of it flooding through you at once.

You can hear Bucky screaming but you can't let go. If you let go, the energy discharge will kill everyone. Will crack the planet open.

So you hold on.

Four seconds. Five. Six.

You slam the stone back into what's left of the pedestal and the world snaps back into focus. You're on your knees, your hands are still glowing, purple veins crawling under your skin like lightning scars. Bucky's hands are on your face, he's saying your name over and over, frantic.

"I'm okay," you manage. Your voice sounds wrong, distant. "I'm okay, I'm—"

You pass out in his arms.

You wake up three days later in the med bay. Bruce is there immediately, shining a light in your eyes, checking your vitals. "Welcome back, how do you feel?"

"Like I touched an infinity stone."

"Well, you're not dead, so, that's a good start." He's trying for levity, but you can see the concern in his eyes. "The glowing has mostly faded, you've still got some residual marks, but they should disappear completely in another few days."

You look down at your hands. The purple veins are still there, faint now, like a spiderweb under your skin.

"Where's Bucky?"

"He's been here the whole time, I finally convinced him to go shower about an hour ago." Bruce hesitates. "He was… he didn't handle seeing you like that very well."

You're about to respond, when the door crashes open and Bucky's thre, hair still wet, looking like he's been through hell.

"You're awake." He's across the room in three strides, hands hovering over you like he's afraid to touch. "You're okay, you're—"

"I'm okay," you assure him. "Buck, I'm fine."

He sits on the edge of the bed, and you can see his hands shaking. "You stopped breathing twice. Did Bruce tell you that? Your heart stopped once, I had to watch them—"

"But I'm here now." You catch his hand, lacing your fingers through his. "I'm right here."

He lifts your joined hands to his mouth, kissing your knuckles. "Don't ever do that again."

"No more infinity stones, I promise."

He manages a weak smile before leaning down to kiss you properly. You don't notice the way his hand tightens on yours or the way his breathing picks up.

Twenty minutes later, he's vomiting in the bathroom.

Bruce runs every test he can think of. Bucky insists it's just stress, just the comedown from the mission, but you all know better.

It happens again the next day. You're sitting together in the common room, your head on his shoulder, and after thirty minutes he has to excuse himself. You find him in the hallway, pale and shaking, leaning against the wall.

"This is connected to the stone," you say.

"We don't know that."

"Bucky—"

"We don't know that," he repeats, more firmly. "Could be a hundred things, could be—"

He doesn't get to finish. His knees buckle and you barely catch him.

Bruce's diagnosis is clinical and devastating: you're still emitting radiation from the power stone. Not enough to hurt a normal person, but enough that Bucky's enhanced metabolism reads it as a threat. The serum is trying to fight it, which is tearing him apart from the inside.

"It should fade," Bruce says, but he won't meet your eyes. "In theory."

"How long?" Bucky demands.

"I don't know. The levels are decreasing, but slowly. It could take weeks, maybe months." He pauses. "Maybe longer."

"So what do we do?"

Bruce looks between you both. "You stay apart, minimize exposure until radiation dissipates to safe levels."

The silence is deafining.

"How much exposure is safe?" You ask quietly.

"Based on today's readings?" Bruce checks his tablet. "Five minutes. Maybe ten if he's had time to recover."

Five minutes. You only get five minutes.

After a few weeks, the lab tests proof that you're safe for fifteen minutes.

You measure everything now.

Bucky sets a timer on his phone every time he enters your room. When it goes off, he leaves without arguments or exceptions.

Fifteen minutes isn't enough time for anything meaningful. It's enough for "how was your day" and "I miss you" and one kiss before the alarm sounds and he has to go.

You start writing things down. All the things you want to tell him, but don't have time for. You leave notes in his room, he leaves notes in yours.

Thought about you today when I saw a cat stuck in a tree. It reminded me of that mission in Prague. -B Sam made a joke about your hair, I defended your honor. You're welcome. -You I'm counting down the minutes until tomorrow, always counting. -B

By week four, your time increases to forty five minutes, and it fels like a miracle.

You can have a meal together now… well, most of one. You learn to eat fast, to tlk while chewing, to fit entire conversations into the space between bites.

"Bruce says the decline is steady," Bucky tells you over breakfast. "If it keeps dropping at this rate, we might have a few hours in another month."

"That's good," you say, but you're both thinking the same thing: What if it stops? What if this is as good as it gets?

The timer goes off and Bucky's only eaten half his food.

"I'll finish it tomorrow," he says, kissing your forehead on his way out.

His plate sits on your table for the rest of the day. You can't bring yourself to throw it away.

By the sixth week, you got two hours, and it feels like the cruelest gift.

It's enough time to watch a movie—if you start it the second he walks in and he leaves before the credits roll.

It's enough time to have sex—once, and only if you're efficient about it, and only if you're both okay with him leaving immediately after. You try it once, the alarm goes off while you're still catching your breath. He kisses you and walks out, and you lie there alone in the tangled sheets and cry.

When the eighth week comes, you notice the increase is slowing down. Bruce shows you the charts, the curve is flattening. The rate of decrease is dropping.

"What does that mean?" Bucky asks.

"It means we might be approaching a plateau," Bruce says carefully. "A baseline level that won't decrease further."

"But it's still going down," you argue. "It went up forty seven minutes this week."

"Forty-seven minutes in seven days. Last week it was an hour and twelve minutes. The week before that, ninety minutes." Bruce looks tired. "I'm not saying it's definitely plateaued, but we need to prepare for the possibility."

That night, Bucky comes to your room. You lie together in your narrow bed, fully clothed, his flesh arm wrapped around you.

"We have thirty more minutes," you whisper. "We should talk about something."

"I don't want to talk."

"Then what do you want?"

"This." His voice is rough. "Just this, just you."

You fall asleep like that. Wake up four hours later to Bucky convulsing beside you, blood streaming from his nose and ears.

"You could've died!" You're shouting, pacing, because if you stop moving you'll fall apart. "You could've— do you have any idea what it was like, waking up and seeing you like that?"

Bucky's sitting on the edge of the med bay bed, still pale but recovering. "I fell asleep, it was an accident."

"An accident? You stayed for four hours, Bucky! Four freaking hours! Your timer went off and you turned it off instead of leaving—"

"I didn't—"

"FRIDAY showed me the logs!" Your voice cracks. "You dismissed the alarm six times, six."

The silence stretches between you.

"I wanted more time," he says finly.

"You could've died."

"I wanted more time with you." He looks up, and his eyes are red. "Is that so fucking terrible? That I wanted to fall asleep next to you? That I wanted one night where I didn't have to watch the clock?"

"Yes!" The word tears out of you. "Yes, it's terrible, because you're killing yourself for a few extra hours—"

"Don't you get it? It's not about hours!" He's on his feet now. "It's about us. Us being together… that's the only thing keeping me—"

The nose bleed starts.

You've been here too long. Twenty minutes arguing, and he's already over the limit.

"I'm leaving," you whisper.

"We're not done—"

"I said I'm leaving!" You're crying now, shoving at his chest before walking out.

You sink to the floor of the next room and finish the fight alone, screaming at an empty room.

Bruce calls you both into the lab. You know it before he speaks, he has a terrible poker face.

"The levels have been stbale for two weeks," he says. "No decrease, no increase. I think… I think this is it."

"It could still drop," Bucky argues. "Could just be longer plateau before—"

"It could." Bruce agrees. "But it's been twelve weeks. The radiation signature should've decreased more by now if it was going to." He pulls up a graph. "I think we're looking at a permanent baseline, aproximately three hours of safe exposure per day."

Three hours for the rest of your life. Three fucking hours.

"There has to be something else," you say, but your voice sounds distant. "Another treatment, a way to extract it, something—"

"I've consulted with everyone I can think of. Shuri, Helen Cho, Strange… There's no precedent for this. Infinity stone exposure on this scale…." Bruce shakes his head. "I'm really sorry."

You're aware of Bucky's hand finding yours, holding it tight.

"Three hours," he says. "We can work with three hours."

You don't answer.

That night, you sit in your room and do the math.

Three hours a day is 1,095 hours a year. Divided by 24, that's 45.625 days. You get 45 days a year with him… the rest, you spend alone.

If you live by 80—optimistic, given your line of work— and Bucky lives to be 150 because of the serum, you'll get 58 years together: 2,668 days total out of 21,170.

12.6% of your life together. The other 87.4% alone.

You're still staring at the numbers when Bucky walks in.

"Three hours a day is 1,095 hours a year," he says, and his voice is so carefully controlled it hurts to hear. "That's 45 days, we get 45 days a year together. Some couples do long distance and see each other less than that. We could— we could make this work, right?"

He's standing in the doorway, hasn't crossed the threshold yet. Even now, he's trying to preserve your time.

"Buck—"

"I wake up at 5, come here until 8. Then lunch, 12 to 1. Dinner, 6 to 8. That's three hours, we just split it up throughout theday. It's structured but it's— it's something." He's talking faster now, desperate. "We could meal prep on Sundays so we don't waste time cooking. We could— I don't know, we could read books at the same time so we have something to talk about during—"

"Bucky, stop."

"No." He takes one step into the room, just one. "No, I won't stop. I've done the math every possible way and this— this is what we have, so we make it enough, we make it—"

"It's not a life."

The words land like a physical blow. You watch him flinch.

"It's our life." His voice cracks. "It is what he have, and people leave with worse. People— people do long distance, people have—"

"People don't get poisoned by the person they love."

"Don't—" The word comes out sharp, ragged. "Don't make this about—"

"What if it gets worse?" You're on your feet now, and you can see the exact moment the timer his head starts counting. He's been here for two minutes. You have 178 minutes left today. "What if the plateau is temporary? What if three hours become two, and then one—"

"Then we'll deal with it."

"What if it kills you?"

"Then it kills me!"

The shout echoes in the small room. Bucky's chest is heaving, his flesh hand clenched into a fist, and you can already see it— the slight tremor starting in his fingers, the way his pupils are dilating wrong.

Five minutes. He's been here for five minutes.

"Get out," you whisper.

"No."

"Bucky, please—"

"No." He crosses the room in three strides, and you can see what it costs him. There's already a slight drag to his left leg—the serum's propioception breaking down. "You don't get to decide this alone… you grabbed that stone to save the mission, to save Steve, to save the entire goddamn universe. You think I'm gonna let that sacrifice be for nothing? You think I'm gonna just walk away after—"

He stops and sways.

Seven minutes.

"Sit down." You grab his arm— his flesh arm, careful now— and try to guide him to the bed. His skin is already too warm. "Damn it, James, sit down before you—"

"No," he's shaking his head and the movement seems to cost him. "Not yet. I can't—I'm not ready yet."

"You're already past your limit—"

"I know." His voice drops. "God, I know. I can feel it. It's like fire in my blood, did you know that? It burns. Everything burns when I'm near you."

Your breath hitches. "You never told me—"

"Because I don't care." He cups your face with both hands, and the metal one is whirring wrong, plates shifting and clicking out of sync. "I don't care if it hurts. I don't care if it burns— the only thing I need is you."

His knees buckle. You catch him, barely, and you're both sinking to the floor. His back hits the edge of the bed and you're kneeling between his legs, holding him up.

"I need one more time," he breathes out. "I need to kiss you one more time without the fucking timer, without counting the seconds in my head, without wondering if this is the one that finally—"

He doesn't finish. Can't finish.

"This is cruel," you whisper as your hands frame his face, and you can feel the fever radiating off his skin. "This is so cruel, letting you stay when you—"

"Then be cruel." His eyes lock on yours, and even unfocused with pain, they're still looking at you with so much love it hurts. "Be cruel, let me have this, let me—"

"It's killing you—"

"You think leaving me won't?" His metal had comes up—jerky and malfunctioning— and catches your wrist. The grip is weak. How could it be? His metal arm is never weak. "You think walking away and leaving without you won't kill me just as dead? At least this way I got to…"

His nose starts bleeding.

It's been ten fucking minutes.

"Please, stop." You sob, reaching for something to stop the blood, but he catches your hand.

"No, please, just—" He's pulling you closer, even though every instinct you have is screaming to push him away, to save him. "Just stay, please. I know we're out of time, I know this is it, I know tomorrow you're gonna leave and never come back, so just— god, please just let me have this."

"How did you—"

"I know you." His thumb brushes your cheekbone. "I know that stubborn look in your face… you've already decided. You're planning on disappear and going somewhere I can't find you, because you think that way you'd be saving me. But baby, I'm not gonna survive without you, you understand that?"

He's crying now, and the tears are pink-tinged. There's blood on his tears. That's new.

"I can't lose you again," he chokes out. "I can't be the one left behind again. I can't wake up and find out the person I love the most is gone."

"Then you have to let me go." You're crying too, your forehead pressed against his. "You have to let me be the one that walks away, because I can live knowing you're out there, somewhere, safe and whole and alive. But I can't live watching this kill you. I can't, Bucky, I simply can't."

"One more time," he whispers against your mouth. "Let me have one more time where I'm not counting… where I can just pretend we have forever."

"We don't have forever…"

"I know. And I know I'm past it, I know I'm gonna pay for this, I don't care."

And he kisses you.

It's not gentle nor careful. It's desperate and drowning. His mouth is relentless against yours, like he's trying to memorize the taste, the feeling, the way you feel together. Your hands are on his hair, on his face, feeling the fever burning through him.

The kiss tastes like copper and salt. And somehow you feel it like the one last thing you'll ever have in your life.

His body is shaking violently now. You can feel every tremor, every muscle spasm. His metal arm is now hanging useless at his side, but his flesh hand is still cupped around the back of your neck, still holding you close as his strength fails.

You break the kiss against to breathe and he makes this desperate, broken sound that breaks your heart and chases your mouth. "Not yet, not yet, please—"

"Bucky, you're—"

"I know." He kisses you again, softer this time, gentler. "Just one more time."

Another kiss, this one starts to taste like blood. His hands are sliding down from your neck, he's losing motor control and his eyes are rolling back. You catch him as he slumps forward, his full weight collapsing into you.

"No, no, no…" You're holding him, lowering him down to the floor, cradling his head. "FRIDAY! Get Steve here! Get Bruce! Please someone—"

Bucky slurs something low, barely conscious. You look down at him with tears in your eyes. "Please, please, stay with me—"

But he's out.

You lay down, screaming until your throat hurts for what it feels like forever, even though it only has been two minutes.

You're still holding him when Steve and Sam crash through the door. Bruce arrives a bit later to the med bay. They try to pull him from your arms and you won't let go.

"How long?" Bruce asks quietly, already prepping an IV.

Your voice barely comes out and sounds distant. "Fifteen minutes, maybe more…"

Steve's face go white. "Jesus Christ."

"Get her out of here," Bruce orders and Sam pulls you away gently.

You watch from the doorway as they work in him. Watch as they load him onto a gurney and wheel him past you to medical.

His metal arm is hanging off the side of the gurney, completely loose. Blood is still trickling from his nose. But on his face, even unconscious, there's this ghost of a smile.

Like it was worth it.

You slide down the wall in the empty hallway and sob, praying in silence for him to be okay.

When Steve finds you an hour later, you're still there. Still staring at the same spot where they took him away.

"He's stable," Steve says quietly, sitting down beside you. "He's gonna be okay…"

You don't answer, looking down at your hands.

"Bruce says the exposure set him back weeks, maybe months. He will need time to recover before…" He trails off but you already know what he means.

Before you can see each other again.

"I'm leaving," you say. Your voice is flat, empty. "Tomorrow, somewhere he won't find me…"

"He'll look."

"I know." You finally look at Steve. "That is why I need you to stop him. You need to make him understand that this is— this is the only way I know how to save him."

Steve remains in silence for a long moment. Then: "He's not gonna forgive you for this."

You close your eyes, leaning your head on the wall. "…But at least he'll be alive."

The next morning, you're gone.

You leave a note on his bedside table in medical, anchored down by a small locket with your initials and a picture of you both inside. You took his dog tags in exchange. The paper is covered in your handwriting, and in some places the ink is smudged.

Bucky,

I'm writing this while you're still unconscious, and I'm trying not to look at you, because if I do, I won't be able to leave. So I'm staring at this paper instead, forcing my hand to move and trying to get all of it out before I lose my nerve.

By the time you read this, I'll be gone. And I need you to understand that this isn't me running away from you. This is me running forward the only future where you survive.

I love you. I love you so much it feels like it's burning me from the inside out. I love the way you still sleep on the left side of the bed just because I asked you once to do so because I felt more comfortable sleeping on the right. I love how you pretend you don't like when Sam calls you "Buckaroo" but I can see you trying not to smile. I love that you learned how to braid hair just so you could braid mine on the nights we actually had time together.

I love you for fighting so hard, for pushing your limits for wanting me badly enough to hurt yourself. But that's exactly why I can't stay.

Last night I watched you almost die in my arms just for some extra time with me. I felt your heartbeat falter under my hands, I saw the blood and I saw you smiling unconscious when they were taking you to the medbay. And that's how I know you're never going to stop. You'll never choose yourself over me. You'll push and push until there's nothing left, and I will have to watch you fade.

I can't do that, Buck. I can't let the person I love most in this world destroy himself for stolen moments and rationed hours. I can't live knowing that every kiss might be the one that finally kills you.

So I'm choosing for the both of us. I'm doing the thing you can't do.

I'm leaving. And I need you to let me go.

I know you're probably already planning how to find me. I know Steve is probably going to help you, and if they ever find me Sam is going to yell at me for breaking your heart, and you're going to pull every favor and every resource until you track me down.

Please don't. I'm begging you baby, please don't look for me.

I know it's not fair to ask, I know I don't have the right, but I'm asking anyway because I need you to live. I need you to have a full life without timers and blood and goodbye kisses that might be the last one.

You've spent so much time being a weapon, being used, being told you don't get to choose. So I'm giving you a choice now: you can spend the rest of your life chasing a ghost or you can let me be the one that got away. You can hold on the hurt or you can let it make you strong enough to move forward.

You probably already know which one I'm hoping you'll choose.

Be happy, James Buchanan Barnes. Be reckless and stupid and alive. Get a cat. Let Sam teach you how to use social media, let Steve drag you to those museums you always pretend to hate. Flirt with someone at a coffee shop, have a one night stand, fall in love again.

Live the life I can't give you.

I'm sorry I couldn't be strong enough to stay. I'm sorry for choosing this way. I'm sorry for every fight we won't have and every meal we don't share and every tomorrow we won't get.

But most of all I'm sorry that loving me turned into something that could kill you.

I'm serious, James, don't look for me. This is the only way I know how to save you.

Always yours, even from far away.

When Bucky wakes up, the first thing he see is the letter. The second thing he sees is that his dog tags are gone. The third thing he realizes is that you are gone too.

He reads the letter and the machine monitoring his heart rate starts screaming.

"No." He's already ripping off the IV from his arm, swaying his legs over the side of the bed. "No, no, no—"

Steve's hands land on his shoulders. "Buck, you need to calm down."

"Where is she?!"

The scream echoes through the medbay. Bucky shoves Steve back hard enough that he hits the wall.

"You need to lie back down," Bruce says, trying to use his calm voice. "Your system is still recovering, you can't—"

Bucky's on his feet now. The room spins but he doesn't care. He's moving toward the door and Steve's blocking it and Bucky can feel it rising in his chest—that cold, dark thing he's spent burying.

"Move."

"You're in no condition—"

"I said move!"

His metal fist goes through the wall next to Steve's head. Sam is there too now, both of them trying to corral him back towards the bed, but Bucky's fighting them… really fighting them. There's blood running down his arm from where he tore the IV out and he can feel his body failing, feel the weakness on his legs, but he doesn't care.

"She's gone!" He's shouting, or maybe sobbing, he can't tell anymore at this point. "She's gone, I have to find her, I have to—"

"Bucky, listen to me—" Steve tries.

"No!" Bucky slams his metal arm into a medical cart and sends it crashing across the room. "You don't understand, she thinks—the letter says—"

He can't get the words out, can't even breathe properly. His chest is too tight and the room is spinning. You're gone.

"We need to sedate him," Bruce intervenes.

"Don't you fucking dare!" Bucky spins toward him and Steve has to physically tackle him. They go down hard, Steve pinning him to the floor and Bucky's still fighting, thrashing, his metal arm whirring as he tries to throw Steve down.

"I'm sorry," Steve is saying and he means it, Bucky hears it in his voice. "I'm sorry, Bucky but you're gonna hurt yourself if we don't stop you."

"I don't care!" Bucky's voice cracks. "I don't care, let me go, let me find her—"

He feels the needle slide into his arm.

"No, please, I have to— she doesn't understand—I need to tell her." His vision is blurring, Steve's face above him, both of them looking wrecked. "Find her, please find her…"

The darkness takes him back.

When he wakes again, it's dark outside.

He's restrained now. Steve's asleep in the chair beside the bed, Sam is gone.

Bucky lies there for a long moment, staring at the ceiling, his body aches and his head pounds. Underneath it all, there's this hollow space where you used to be.

The letter is folded on the bedside table. They must've picked it up after… after whatever happened. He doesn't remember all of it, just the rage and the panic, the desperate need to move, to chase you and fix everything.

But he's not panicking now, he's thinking.

What if all of it wasn't permanent? What if there was a cure? Bruce said there was no precedent for infinity stone exposure like this. No treatment, no solution. But Bruce doesn't know everything. Bruce couldn't save Tony.

Bucky's mind was starting to work, clicking through possibilities: Carol Danvers got her powers when she was exposed to the space stone. Wanda's powers were the result of an experiment trial with the mind stone. Peter Quill was exposed to the power stone, along with his team, according to what Steve told him.

There were options. Leads. Possibilities.

And if none of them worked, he would find new ones. He'll search every corner of the universe if he has to. He'll make deals with gods and monsters and anyone else who might have answers.

The restraints are loose enough that he could break them. They're meant to slow him down, not stop him. But he doesn't move. He just lies there, breathing steadily, his mind cataloguing resources and contacts and next steps.

He reaches back for the letter and reads it one more time.

I'm serious, James, don't look for me. This is the only way I know how to save you.

He folds it carefully and picks up the locket you left there, a picture of the both of you staring back at him. He closes his hand around it and presses it against his chest.

"I'm going to solve this out," he murmurs quietly, low enough to prevent Steve from waking up. "And then I'm going to find you, and we're going to have forever. I promise."