Walker is not backing down, and when Bucky gets flung across the warehouse into a generator, Sam's heart stops. Electricity goes flying and Sam and Walker both stop and turn as sparks jolt through Bucky's body and he lets out a scream that Sam can only describe as agonized. The whole thing lasts maybe seconds before Bucky's body settles on the concrete floor, Vibranium arm under him and no movement remaining in him.
Sam bolts toward Bucky. He doesn't care about the fight now, not now that his partner is on the ground, unconscious. Thoughts of Riley rip through his mind and he drops heavily to his knees at Bucky's side, reaching out hesitantly until he's sure there's no residual energy. He turns Bucky onto his back, checks for breath, for a pulse. There's nothing.
Sam looks up and over at Walker, who's taken several cautious steps their way, shield dropped and forgotten. It doesn't matter right now. The shield will have to wait. Sam turns his attention back to Bucky. Bucky is what's important. Steve may have given Sam the shield to look after, but he also left Bucky under Sam's watch and Sam has grown all too fond of the cyborg in this short time. He's yet to face his true feelings for the other man, but this time working together has made it all too clear that Sam's attraction to the man goes beyond the physical, and sitting over what is essentially his corpse right now is not making things any easier to accept.
He shakes his head to clear it a bit, then bends to start CPR. He can hear Walker step closer, shuffling uncomfortably. He wants to tell the other man to call for help, be rational, do something, but if he stops even for a moment, that's time lost on saving Bucky. He can't lose that time. He has to get Bucky breathing again. He has to get that heart going. No matter what.
He loses track of how many breaths he's given, but his arms are going tired and he heard Walker step away a bit ago. He didn't pick up the shield for whatever reason, so Sam thinks maybe he went to get help and he'll be back, but there's no telling. Sam's here until he gets Bucky back or until he can't do this anymore. Whichever comes first.
He finds himself thinking, between the counts and breaths, about Bucky's eyes. He wants to see them open again. He wants that blue directed his way again, even if it's in irritation. He wants to hear the sarcasm in that voice one more time. He wants color in those cheeks, wants to see them pulling up in that tight smile that's Bucky trying to hide the fact that he's amused.
He knows he's been too focused on the other man. He knows he's lost himself in Bucky the same way he did in Riley. He knows he's headed down the same path of self destruction with Bucky, especially if Bucky doesn't make it, but goddamn it, he thinks he's falling for this asshole.
His arms are going numb and he doesn't know how much more he's got in him, but then Bucky suddenly coughs and gasps for breath under him and his right arm shoots up, gripping Sam's shoulder weakly. It's a start. Sam keeps going just a little more, waiting for another breath, a squeeze of those fingers, and then-
"Sam- Sammy, I'm-" Bucky's voice is broken and rough. He's coughing, but he's breathing more fluidly and Sam can finally stop. He stills his arms and sits back just a little. He doesn't lean back enough to break their connection. Bucky's hand is still on his shoulder and his hands are still on Bucky's chest, but he stops pressing down.
Bucky's eyes open and he looks up at Sam, gasping softly again. He swallows heavily. Sam watches his throat move with the action, Adam's apple moving, life coming back to the man. He watches color starting to speckle along Bucky's cheeks, the lines around and under his eyes easing just a bit, but still there. Still Bucky.
Bucky takes a shaking draw of breath and coughs again, then finds Sam's face with his eyes, locks their eyes together. He smiles weakly, gives a shaky laugh, and squeezes Sam's shoulder.
"Sam."
Sam has never heard his name whispered like a prayer before, but this is close. Bucky's watching him with reverent awe and he watches a mix of emotions pass behind those beautiful blue eyes.
"You know you're not allowed to just go out on me like that," Sam says after a second. "You still owe me a coffee."
Bucky laughs, the sound raspy and stilted, but whole and warm and alive. Sam feels tears spill over his eyelids and cheeks and he lets a sob fall from his lips. The hand at his shoulder shifts, fingers finding his cheek, pressing into the skin and pushing the tears away. Sam grips at Bucky's hand and cries harder.
"Don't leave me, Buck."
Bucky swallows again, nods carefully, and smiles softly. There are tears in his eyes now, too.
"Sammy, I'm here," Bucky whispers, and the emotion in his voice is so much more than Sam ever heard. It's thick like syrup and full of warmth and promise. "I'm not goin' anywhere, Sammy. You're stuck with me."
Sam lets out a broken laugh and nods again. "Damn right. You're not going anywhere unless I'm by your side, you got that?"
"Always, Sam," Bucky sighs, resting his head back a moment and letting his eyes fall closed. He smiles and takes a deep, steady breath. The first steady breath since waking. "You're my number one, doll."
It's the first time Bucky's ever said it, but it feels like he's been hearing him say those words forever. It's a promise specifically for Sam and he understands now, with such clarity, exactly how he feels. He understands Steve. He understands, 'Til the end of the line.' He understands it all.
Sam leans down, pressing his lips to Bucky's forehead. "You're my number one, Buck. Never anyone else."
By the time Walker returns, help in tow, the two have long since abandoned the place, and the shield is gone with them.