Warning: Two ship high in transits, one son of a female dog, lots of references to the underworld, two God condemn its, and suicidal thoughts. This is the big one.

The lab was quiet.

Tony's lab was never quiet.

There was no music. There was no whir and grind and hiss of machinery. The robots chirped in alarm and hid away in a corner as soon as Steve and Bucky stepped inside.

Tony was a mess, exhausted and haggard, his eyes red, his cheeks sunken and unshaved. He looked like he hadn't slept for weeks. He probably hadn't.

Bucky sat down on the workbench. The chill of cool metal bit into his thighs. Something he'd stuck in his pocket on the way here jabbed him in the hip.

He knew what he had to do if things went south. He knew what he had to do.

That didn't make him any less afraid.

Steve took a swivel chair beside him, silently offering support. And Tony, who'd stood hunched over a nearby desk, turned around, fiddling with something white in his hands.

It was an envelope. The top had been torn open, and then hastily re-shut.

Bucky could feel a drum pounding in his chest.

"So," said Tony, staring right at him. "Are we gonna talk about this?"

Bucky's tongue clung to the roof of his mouth. There were a million things he wanted to say, but he couldn't think of any of them.

Tony hadn't moved. Looking at him felt like staring down the barrel of a loaded gun. "Do you remember them? Your parents?"

Bucky looked askance. No, he didn't. Steve had told him their names—George and Winifred—and he could recall small details—she had soft hands, and he had a dark mustache—but he couldn't remember their faces.

He didn't know if that made him better or worse off than Tony.

He just shook his head.

"Well, shit!" spat Tony. He was angry; angry at what—or at whom—Bucky had no idea. "That's too bad! 'Cause I do."

Bucky was confused for a moment, and then, he just became heartbroken and afraid.

Tony threw the envelope down on the desk and stalked toward him. "Dad was always disappointed in me," he hissed, shoving his hands in the pockets of faded jeans. "I was his only son, and not the whole time he was alive did I ever get a kind word out of 'im.

"Mom was a saint for putting up with him." The words were nicer, but Tony's voice was spitting. "She tried, really, she did, but I just sucked, as a kid, y'know? Never pulled my act together, never showed them anything better, 'cause I never got the chance."

Bucky looked askance and shut his eyes.

He was the reason Tony never got a chance.

A car, a tree, a dark road...

Tony stayed there for a long moment. If looks could kill, Bucky would have been six feet under already.

Then, Tony turned to Steve.

"Y'know, I think it was right after D.C., right, Cap?" There was a lightness in his voice, but it was clearly fake, and that was terrifying. "You called me up for a little help on your missing person search, took up my whole morning, interrupted the dinner party that I had scheduled that night—thank you for that—to tell me you found some dead German scientist programmed into a computer in Jersey—"

"Swiss," Steve said weakly, staring at the swivel chair's arm.

"Swiss!" cried Tony. "Wow! My bad! And what did the dead Swiss AI have to say?"

Now it was Steve's turn to stare down the loaded gun. He took a deep breath. "I didn't know anything for sure—"

"Spit it out, Rogers, this is rhetorical."

Steve's jaw twitched, but he pressed on. "He didn't say anything for sure, but he implied—"

"Implied."

"That your parents accident," he said slowly, "was a HYDRA set-up."

Bucky sat petrified.

Tony turned and stared right into him. "And how many assassins does HYDRA have?"

Bucky couldn't believe it. All along, Tony had known. He'd had an inkling, he'd known there was a possibility, so why? Why had he welcomed Bucky in? Why had he taken that chance? Why, why, why, why—?

Steve stepped in gently, with the same voice he used when Bucky was wound up from a flashback and about to punch something. "We know you're angry, Tony—"

"Like hell I'm angry!" Tony roared, and his arm swung out wide. "My mom is dead!"

Steve put his hands up in surrender. "That's why we had to tell you, as soon as we knew. We couldn't hide the truth from—"

"Y'know what, I almost wish you didn't," Tony hissed. "So I wouldn't have to know what the hell that you brought into my Tower!"

Steve winced.

"Is this how you thank me?!" shouted Tony. "This is the thanks I get? S.H.I.E.L.D. is gone, Rogers, you wouldn't even have a paycheck if it weren't for me, and I open up the Tower—my Tower—when you wanna invite your brainwashed assassin buddy with the cottage cheese brain over—!"

Bucky cringed and covered his ears.

"I didn't know it was him—"

"No, shut up, I'm talking."

"It wasn't him!"

"I said shut up! Shut the hell up!"

Bucky had heard enough.

He knew what he had to do.

He stood, and the knife from his pocket flicked open.

Steve saw it first. He blanched and yanked Tony out of Bucky's reach.

"Rogers, what the hell," snapped Tony, writhing out of his grip, but then he saw the blade and paled.

Bucky's hand was shaking.

"Buck—" began Steve. "Bucky, it's fine, he's not gonna hurt me—"

Bucky turned the knife around. His fingers grasped sharp steel, and the handle faced towards Tony.

Tony just stared.

"If you're going to do it," Bucky said, his voice carefully controlled, "do it now."

Steve gaped. "What—?"

Tony stared at his face, and then at his hand, and then grabbed the knife and yanked it. Bucky felt a sharp pain, and then there was a thin cut in his skin.

Bucky lifted his hand, shakily. Blood had trailed down his palm and curled around his middle finger, and now it snaked towards his wrist.

"I can't make it right. I can't bring 'em back." He was staring down the guillotine, and though it broke his heart, he put his head underneath. "But you can finish it."

Steve flew to him, dragging him back, arms around his shoulders. "Buck, stop it! It wasn't you!"

Bucky shoved him off. "Shut UP!"

Steve took a step back, hands raised helplessly. His eyes flashed with betrayal and hurt.

For a moment, Bucky hurt for him too. All he wanted was for his best friend to get out alive, and here he was, willingly walking into the flames.

But he had to understand. Steve had to understand. He had to know he couldn't leave without the wrong made right.

"I did it," rasped Bucky. His arm was extended toward Steve, his face pleading for him to understand. "I didn't want to. But it was my finger on the trigger, and I did it."

Steve opened his mouth and shook his head, but no sound came out.

But I love you! he seemed to scream, wordlessly.

I know, Bucky answered in kind. And I'm sorry.

"I'm sorry." His voice was shaking, pleading. "Let me make it right."

Steve took a deep breath and lifted his chin. His teeth grit, his face crumpled, and his chest hitched in a sob before he turned away.

It punched Bucky in the gut.

Steve didn't cry. Steve never cried.

But he turned away, to Tony, who stared between him and Steve with a look like a cornered dog about to attack.

Bucky grasped his wrist and lifted the blade to his neck.

Tony's face was a foot from his own. Brown eyes, full of anger and hurt and grief.

Bucky lifted his chin exposing his throat. He swallowed heavily and shut his eyes. "Make it quick."

"Oh, god, no," Steve choked into his hands.

For one long moment, they stood there, unmoving.

Every second, Bucky expected to feel a bite in his throat, and a wheeze as his last breath left the hole in his windpipe. Every second, he expected it all to be over, to feel the pleasant dark to take him, one last time.

Instead, he felt a kick to the chest.

Bucky stumbled backward. The back of his knees hit the workbench, and his eyes flew open.

There was Tony. Head down, knife in a shaking hand.

He swung his arm—

THUD.

Some complicated-looking machine now sported a dent, and a protruding blade.

It hissed, fizzled, coughed sparks, and died.

Bucky swallowed hard.

That could have been him. That should have been him. Why—?

Tony grabbed him by the collar. "You owe me, Barnes," he hissed, an inch from his nose. "You owe me, big time. So I'm gonna ask one question, and you're gonna answer it, and I just saved your life so you'd better do better than 'I don't know'. Do you understand?"

Terrified, Bucky nodded.

"Who sent you out there?" Tony's voice was dangerously low. "Where is he?"

Bucky gaped. It took every ounce of brainpower to translate that. "My handler..."

Tony turned away and muttered, "Shit." Louder, he seethed, "Yeah! Sure! I guess people have handlers now, like some kind of sick goddamn dog show! Yeah, handler, dispatcher, slave driver, whatever you call it, where is he?"

"I—I don't—"

"What did I just say about 'I don't know'?"

Bucky shut his eyes and racked his brain. Of course it stopped working, right when he needed it to. He scrambled in the dark for something, anything, anything that would help, before an image of manila folders popped into his mind and his frown cleared. "My files..."

Tony was watching him like an angry dog.

Bucky's lips twitched upwards into a grim smile. "I found some of Their bases, while I was still out in the rain. Burned them down, mostly. Grabbed anything that looked important." He frowned. "I kept some files in a parking garage, but...they disappeared."

Tony's hope drained right back down. "Well, a damn lot of help that is, huh?"

Bucky hid in his hair.

That's when Steve said, "Can I talk now?"

Bucky snuck a glance at Steve. His eyes were red, his voice was wobbly, and his jaw was pressed in a firm line.

Bucky felt just terrible.

Tony was impatient. "Only if you're helping."

Steve's breath hissed through his teeth. He nodded, pointedly avoided Tony's eye, and spoke to Bucky. "Clint found your nest."

Bucky's eyebrows jumped up.

"Part of what helped him track you."

Bucky whispered, "Clint has them?"

Steve nodded. "Brought 'em back to the Tower for safe-keeping."

"Well, tell Feathers to cough 'em up, let's get moving," said Tony.

"The..." Bucky's eyebrows furrowed, and he shut his eyes. "The Triskellion leak..."

Tony snapped his fingers and started walking away. "I'll tell Miss Muffet to do another data search. We're gonna find—" he grunted, yanked the knife out of the computer and flung it onto a table, "—that son of a bitch, and you're gonna hold him while I punch his nose back into his skull!"

Bucky watched him go. He couldn't believe it. He couldn't believe he was seeing this, he couldn't believe they had a plan, he could hardly process—

Steve tugged him to his feet.

The next thing Bucky knew, he was swallowed up in two strong arms.

"Promise me something, Buck." Steve was an inch from breaking down.

Bucky reached his arms around him, as far as they could go—his right hand, still red with blood, he curled into a fist, and the metal fingers clutched the fabric of Steve's shirt—and he nodded.

Steve held him tighter, like it would make the whole world stand still. "Promise me you'll never do that again."

Bucky could feel hot pressure welling up behind his eyes. He buried his head in Steve's shoulder.

Please, please, please, don't make me ever go on without you.

Not without you.

This time, when he nodded, it was a promise.

As long as he lived, he'd never put the gun—or a knife—in another man's hand, not ever again.

If Tony could forgive him, maybe he could forgive himself.

"Thank you." Steve's chest hitched, but no sound came out, and Bucky could feel him shuddering.

Bucky burrowed deeper into him. He hated when he made Steve cry. "I'm sorry."

Steve gave a half-laugh, half-sob. "No, no, it's okay." His jaw was against Bucky's scalp, and his next inhale sniffed back tears. "I'm proud of you."

Bucky didn't answer. He could still see the red, open cut on his hand.

Steve patted his back, and when he spoke again, it was determined. "We'll make this right. We've got a plan, and we're gonna make this right."

Bucky didn't know if Steve was talking to him or to himself, but he smiled weakly, shut his eyes, and let his right hand fall limp.

The laboratory floor was stained red, but only with five little spots.

A/N: Just in case you ever think I'm not anal-retentive about continuity within my AU, here's your explanation as to why Bucky's folders disappeared in The Run and Go Chapter 6! You can laugh at me, but the joke's on you, I'm already laughing at myself.