As the nose of the Valkyrie dips toward the frozen ground, Steve takes a deep breath, bracing himself, then leans all his weight into the steering yoke until it's pressed flat to the dashboard. He fights the controls down into a neck-breaking dive and pins them there. The ship is swiftly picking up speed. This is it. The end.

His mind catches on Peggy, wincing when her panicked voice crackles out into empty static over the radio. It's the last time he'll ever hear that voice, and he misses it already. He's not going to make it back.
Everything around him begins to vibrate, humming and weightless, as the plane plummets. Not much longer now.
Steve lets his eyes slip closed for a moment. He knows that he's hurting her… He made Peggy cry - something he can't recall her ever doing before. Could hear her trying to bite it back so it wouldn't carry in her voice. He hates himself for doing this to her, but there's just no other way. This is how it ends. This is his choice.

He runs his tongue pensively over his bottom lip. The waxy taste of her lipstick still lingers faintly there. Peggy kissed him, for the first and only time, just before he leapt out of Schmidt's car. She'd just grabbed him by the front of his star-spangled uniform as he coiled for the jump and hauled him in, sealing her lips over his and leaving him dizzy and breathless before she was done. Steve had been too stunned to remember where he was for a few moments by the time she let him go, and stared helplessly at the colonel for direction instead. The colonel had just told him to hurry the hell up.

Steve isn't stupid. He knows why she did it; and it wasn't some reckless romantic gesture. Peggy is a rock, measured and steady at all times. She never acts out of desperation. That wasn't a panicked, heat-of-the-moment decision back there. It was a promise. She was illustrating what would be waiting for him when this is all over. Promising a thousand more moments like this. Begging him to be careful and not take his usual crazy risks. Reminding him that there are still people who love him, want him to come home…

And Peggy does love him. He knows that. Why, he's not quite sure, but he doesn't dispute the truth. He loves Peggy too. Loves her more than he can ever express, but that's exactly why he can't just go back and pretend to be alright. He has to admit, though, it hurts to realize that he'll never kiss her again. Never even see her again.
If things had just been different…

But they're not different. He got his best friend killed out here, and he can't go home and pretend like that's not his fault. Pretend that he'll get over it.
Steve can't take the thought of going back to his old life, no more missions to distract him, no more war to keep him busy, and spending the rest of his life turning around, expecting to find Bucky in the kitchen, or dragging himself, half asleep, out of his creaky old bed in search of coffee. He'd always be looking over his shoulder, always be disappointing himself.

Peggy would see it. She's much too sharp to miss the signs, and he wouldn't be able to keep his grief from her for very long. She'd know he was drowning, and she'd ache for him every day. Try to share his burden and be crushed under it, right alongside him.
Steve can't be the man she deserves. He never could be, but especially not with Bucky's ghost just over his shoulder. Peggy would never let him suffer alone, but he can't stop hurting and he'll only ruin her life too, if he goes back to her. He won't do that to her.

And that doesn't even touch on the nightmares…
The nightmares are- God... he can't bear even one more night of them.

Steve isn't up to waking panicked, choking on tears, every day for the rest of his life. Sometimes because he dreams that his best friend hasn't really died. Dreams that Bucky comes swaggering back through the door with that crooked smile on his face like nothing happened, cracking wise that it'll take a lot more than that to get rid of him. Steve always wakes up from that one in a cold sweat, suddenly alone, and turns the barracks room upside-down before he can accept that it was just a dream.
Other times he just finds himself clinging to the side of that train again, wind tearing at his face, and watching Bucky fall. Again. And again. And again. Over and over, until he wakes up screaming and shaking in his bunk. It's been this way since Buck fell.
The worst part is that none of it is even new; just worse. He's been struggling with night terrors and horrifying dreams since he first saw combat, but he hadn't realized how much more painful they could get.

Steve hasn't had a real night's sleep in months.
He's exhausted, and heartsick, and ...he just can't do this anymore.

The momentum of the rapidly dropping plane is pressing him back in his seat and he knows there can be only seconds before he slams into hard arctic ice. He lets out a slow, steady breath, and braces himself for it.
This, he can do.

The Valkyrie's impact hurls him bodily out of his seat and hard into the windscreen, cracking the glass into an impressive spiderweb design around the crown of his head. The ship rocks and bucks as it skids, and he pinballs off of the control panel, a wall laced with painfully knobby rivets, the unyielding bulk of the captain's chair, then finally ends up curled around himself on the floor, half under the seat; battered and bloodied, as the massive bird finally grinds to a halt, firmly wedged in the ice.

Slowly, Steve rolls onto his front and crawls gingerly up to his knees. He definitely cracked -possibly broke- a couple of ribs on the steering column. Might've gotten a concussion from breaking the glass with his skull... His right leg burns and won't support weight. He tries to lever himself up - hisses and crumples sideways when there's pressure on his left hand. Teeth clenched, he sinks back against the front of the control box and cradles the arm against his chest. Add a splintered wrist to the list, then.

It won't be long at all now, at least. The plane is badly damaged. It's going to sink and, when it does, he'll go down with it. He surprises even himself with how relieved that makes him; thinking of the impending end. How good it feels to just surrender, to let death come. He's been fighting it all his life, and he's so, so tired of fighting.

He could make a bid for freedom, he supposes. Even injured, he could probably crawl to an escape hatch and haul himself out. Drag himself across the ice until his strength gave out, and hope for a rescue team to spot him.
...But they'd never find him. How could they? He has no idea where he was when he went down, but the plane certainly bounced and skidded as it came down. He's probably miles and miles off course by now. He could go through a lot of pain and struggle to ultimately freeze to death on an ice-floe, or he could just lie here and give up. What's the point in struggling if the end result is the same either way?
He lets himself slump.
He chose this. He can accept that it's over.

Feeling a little dizzy, Steve lets his head fall back against the cold metal paneling behind him, closes his eyes, and fumbles for his compass. For a moment, it seems to be lost, but eventually his fingers scuff across the dented case and he drags it to him. He blinks wearly at it. Peggy's picture is still jammed tightly in the lid, no worse for wear from his crash landing. He kisses the tip of one finger and traces it softly over her face.

"G'bye Peggy… I'm sorry."

He stares at her for a long moment until he hears the hull creak, low and ominous, before it fractures violently when the ice shifts. He has only a few minutes left before the cabin floods. Might as well get comfortable...
He snaps the compass shut with a firm click and tucks it under his uniform in the safest place he can think of. The chilly metal just over his heart is comforting somehow, even if it's giving him goosebumps.
Weary beyond measure and flat out of willpower, he lets himself slide down the hard, battered panel at his back until he's lying flat-out on the floor. He carefully sets his injured hand protectively over the lump of the compass, cradling it. No one will ever find his body out here, but he'd like to preserve what little he has left of Peggy as best he can. Her image is as safe as he can make it.

Just one more thing to do before he can slip away...
Fingers trembling, he reaches out and finds his shield, drags it closer to him and lets it rest against his hip. He isn't going to need it now, but it's a familiar comfort to have it close. He can let himself indulge in little comforts now. And why not? How much longer will it matter what he indulges in?
He sets his head down and closes his eyes, both hands coming to rest gently over the bump of the compass under his clothes, settled in the center of his chest. He's ready to face the end now.

A prickle of frigid cold lances up his spine. There is icey water slowly flowing in around him, burning and numbing his skin as it soaks into his clothes. He shivers, but pays it no real mind. He wonders idly if he'll freeze to death or drown first. It could go either way, at this point. It doesn't really matter, though. The water will fill the cabin soon, and he'll be too dead to care by then.
He doesn't bother opening his eyes to watch his last moments unfold. He doesn't want to take this part with him into the dark.

Goodbye Peggy. I'm so sorry. he thinks again as the edges of his thoughts begin to dim and blur.
Bucky... I'm coming. I'll see you soon.

And then everything quietly,slowly, fades away.
The Valkyrie sinks slowly beneath the ice, and vanishes for 70 years.