The end of the world happens before Bucky even knows it: he wakes up in a town he doesn’t know, walks to the diner across the street, and pushes open the door to see the waitress standing, staring stock-still at the tv hanging from the corner of the room.
The Avengers are dead.
Bucky makes a sound he didn’t realise he could make any more, a noise at the back of his throat like an echo (not without you)- he walks out of the diner without saying anything and looks in the direction of Manhattan. Onscreen, the camera shows a tattered scrap of blue among the rubble, a tangle of red hair dull in a way it’s never been before, before blinking into blankness.
Bucky clenches his fists, the steel one hard enough to leave dents in the metal, gears grinding under the strain.
How didn’t he know?
He doesn’t have a way of understanding how to be in a world where Steve isn’t.
The feeling doesn’t get any better in the days to come. Some days, he mourns for Steve, some, for Natasha. Something in him shuts down, too hard and hot and raw to feel- he sleeps with his jaw and fists clenched tight, his eyes screwed shut. The world continues to end. This is, at least, appropriate. He stays ahead of Ultron’s minions as much as he can, running from the tide of devastation that rolls out from New York.
A couple of kids try to rob him as he sleeps in his truck (it isn’t actually his truck, but the owner’s three towns away, so Bucky figures it’s as much his now as anything). The first he knows of it is when the hand (he thinks of it as the hand, not his hand, even now) has closed around a grubby wrist.
The kid looks at him, too tired and hungry to be scared, and Bucky persuades his fingers to open. He points them out of the town. That’s about as much as he can do.
The arm makes him an enemy for most of the people he meets, something to be feared now they’ve seen how like a man a machine can become- how petty, how hungry for blood. The habit of covering it serves him well, but he starts to rely on it less, and sometimes he wakes from nightmares where the silver spreads across his skin and up his neck, down into his mouth and over all his bones.
It doesn’t seem to respond to Ultron’s signal, whatever he’s using to control the machines. Bucky tests it by getting as close to the cities as he dares: nothing happens except an ache, too small to be anything other than imagination, along with an urge to curl and uncurl his fingers. He fits them to the dents in his palm, and turns away. All he can do now it keep running.
They find him outside Washington- a dangerous place to be. He’s been testing the arm again, watching for weakness in Ultron’s silver foot soldiers. They don’t capture him so much as herd him- he’s running through broken buildings and suddenly he stumbles into a camp, a woman with tired eyes and hair pulled back into a ponytail, another face he doesn’t recognise.
"What are you?" he asks, taking in the worn camo gear, the badly-maintained guns. "The resistance?"
(Sam had fallen, broken, from the sky. Pepper evaporated with the tower. The gods of Asgard are silent. Who is this, walking from the smoke?)
The woman gives him a thin, tight smile.
'If you want to call it that. I'm Jane Foster.”