Tony didn't know what the final straw was exactly. No matter how many times he looked back across the years, he couldn't quite pinpoint the moment he crossed over the line he had drawn in the sand. He couldn't determine what triggered his propulsion past the point of no return. He tried, once, by compiling a list of anchors and using the process of elimination to determine who had been the last to let go.

Obadiah Stane went first. He had been the first person—or at least, the first person Tony actually cared about—to stab the young billionaire in the back, and the betrayal had planted the first seeds of distrustful paranoia. If Tony couldn't trust the man who had been his mentor for more than a decade, how could he trust anyone? If there was one person in his life who was skilled in the art of manipulation and deceit to that degree, how did he know they weren't all like that?

Tony told himself he was overreacting. Obadiah was an outlier. Life went on.

Then he started dying. His arc reactor was killing him, and he knew he didn't have long to say goodbye. Unfortunately, he had never been very good with words, and he didn't know how to breech such a morbid topic with the small group of friends he still valued. Instead, he began to act strangely in the hopes they might notice. It was difficult, given his usual range of shenanigans, but he thought the abnormally raucous parties, risky behavior, and discarding of personal objects would get someone's attention.

He thought wrong.

Those Tony had hoped were close enough to understand only saw the action, not the fear behind it. Pepper. Rhodey. Happy. They all walked out on him, one by one, and that was when he knew his doubt and distrust was warranted. That was when he learned if push came to shove, eventually, everyone would turn on him. Then again, if he could keep the push from coming and shoving, it wouldn't be an issue. His hope was marginally restored, and he did the best he could to keep everyone safe and happy.

He tried too hard.

He gave too much in the Battle of New York. He nearly died to protect a world that had never given him anything but trouble, to save a team that could barely tolerate him, and it broke him somehow. It carved out a little piece of his sanity and filled the empty space with nightmares and anxiety, a suffocating panic flooding his body at the mere mention of the incident. It was sucking the life out of him, and yet, he still tried to use what resources he had to protect the people who relied on him.

It didn't work.

Too many suits, she said. Too much time in the lab, she said. Too paranoid, too isolated, too reckless, she said. But what else could he do? What was the alternative? She never gave him with any options, she only told him what he did wrong and then left. Again. Thankfully, it wasn't long before he was given the chance to fix his mistake. Someone put them both in danger, and he was able to get back in her good graces by putting his own health and safety aside for her sake. He gave up his suits, the only sense of security he had left, and he watched the light in her eyes as the creations he had poured his heart and soul into came crashing down in spirals of flaming debris. Rhodey got to be the hero, the wingman who saved the President of the United States, and Tony was sure he loved that. Things settled back down between the three of them. Somehow, he had yet to screw up badly enough to ruin everything.

But then he did.

Sometimes, Tony thought Sokovia was the breaking point. Jarvis had been killed, broken down and reconstructed into something that was too detached, too basic, too child-like to be him. Bruce had disappeared without a word, without a phone call, without a letter, without anything to ease the inventor's anxious mind. Everyone blamed him for the creation of Ultron and subsequent destruction, and just a few months after the dust settled, Pepper had said those famous words and packed her bags.

"I think we need to take a break."

That certainly could have been the breaking point. But, then again, maybe it wasn't.

Maybe it was the Accords. Maybe it was the sensation of three people he still believed he could trust stabbing him in the back over, and over, and over. Steve chose Bucky over Tony. Clint chose Steve over Tony. Natasha lied to Tony's face and chose Steve over him, and then she had the nerve to call him on his ego. Then Clint had the nerve to say Tony was the backstabber. Then Steve had the nerve to choose Bucky over Tony again and try to wriggle his way out of admitting he had kept an earth-shattering secret from his so-called friend like the slimy, star-spangled hypocrite he was.

One by one, Tony watched them walk away and leave him a little more vulnerable than he was before they tore off another piece of his quickly crumbling shield. He began to wonder how much he had left in him; how many blows it would take before he finally went down and didn't come back up.

Those old fears he had nursed on and off for years returned with a vengeance, and he once again realized the painful truth of his situation. They all had something they valued above Tony's friendship. There was no point in negotiations or treaties because there was nothing to protect. They all had backups for when he fell through, so there was no reason to fight to keep the Avengers together. There was no reason to compromise because they simply didn't care.

He was down to one friend, one person he could still trust, and that person was Rhodey.

"Have you calmed down now, or is there still a little tantrum left in you?"

Steve glared at him, eyes red and puffy and marbleized by tears.

"That's not much of an answer." Tony glanced down at the bloodstain on the floor and whistled. "I think I got a little carried away. I'm typically very clean about these things."

Steve grit his teeth, making a noise that was some sort of cross between a snarl and a hiss. "You—"

"Language," Tony sang, wagging his finger in the captive's face. "You remember that little running joke, right? We had a lot of fun with that. I'll be honest, I've kind of missed it."

Steve pulled against the chains holding him spread against the wall, breathing hard and visibly torn between his anger and his grief. "What—what happened after I left? What happened to you, Tony? Why would you—when did you become… when did you become this?"

Tony laughed before he could stop himself, a high-pitched giggle that lasted no more than half a second bursting up his throat. "You say that like you don't already know."

"I don't know," the man insisted, his anger quickly losing the battle for dominance as a sort of desperation crept into his eyes. "I don't know how or when or why the man I knew became the man standing in front of me now."

Tony chuckled, shaking his head and approaching the prisoner with a smile. "Nothing happened to me, Stevie Boy. I just got tired."

Steve swallowed and pushed back into the wall as Tony reached out to cup his chin, scarred fingers brushing lightly against the bruises left over from a brutal capture.

"I got tired of being everyone's second or third or fourth choice. I got tired of never being a priority to anyone, even myself. I got tired of people shooting me in the back with my own weapons when my guard was down. I got tired of giving up everything only to have it all thrown back in my face." Tony smirked lightly and watched as confusion and anger and pain fought for dominance in the soldier's glassy, blue eyes. "I got tired of being the good guy."

Panting, Steve tried to shake his head. "That's not an excuse. We all lost—"

Tony burst into hysterics before Steve could manage another word, his laughter echoing back at them in the large, empty room. "Oh, no. Please don't tell me you were about to say you all lost everything at one time or another. Because if you were, I might have to snap your neck."

Tony's hands moved suddenly, abandoning the prisoner's face in favor of a throat raw from screaming. "You're right, Steve, you did lose things. Sometimes, you lost everything. But that's just it. You lost them, and that makes you a victim of circumstance. I gave up what I had, and that makes me a victim of nothing but my own mercy and goodness." He jerked the neck in his hands, lifting him from the ground just enough to make him squirm. "Your best friend is dead, and you get to blame me for that for the rest of your life. You will go the grave cursing my name for that. My best friend fought alongside me because he believed in me and what I was doing, and he—" Tony grit his teeth, his own eyes burning as his grip tightened. "Rhodey is dead, and I have no one to blame for that but myself. So don't you dare compare your situation to mine, Rogers. Because it is hard to lose someone you love, but it is so much harder to give them up."

Steve inhaled slowly through his nose, feet struggling to find traction on the metal walls, trying to stay calm and conserve his oxygen. Tony let him struggle for a moment and then dropped his hands down to his sides, scoffing with a bitter smile.

"Do you want to know the worst part, Steve? Every time I gave something up, it was to protect something I thought was bigger than myself. I tried to keep the world at peace, and I tried to keep governments united, and I tried to help as many people around the world as I possibly could, and do you know what? They spit in my face. It didn't matter how many people I saved, how much money I gave, or how much I had to surrender in the process; there was always something I did wrong, something I missed, some failure or shortcoming that resulted in tragedy."

Tony threw his hands up and shrugged as he swung in a circle, beginning a casual pace back and forth in front of his victim. "I finally said 'screw it,' and started doing things my way. Planet Stark. I dismantled every government, shut down big businesses, and obliterated military forces internationally. Now I just sit back and watch. I watch all of those people who are alive today because of what I gave as they scrounge around in the dumpsters and sewage pipes to find what they need. No more handouts, no more bailouts, no more help-you-outs. Because if they're going to be slandering me and cursing my name, I figure I might as well give them good reason to."

Steve watched him, a baffled expression shadowing the righteous fury and hollow pain that had previously been flickering back and forth across his features. He shook, pulling uselessly against the restraints that held him fast, chest heaving as he sucked down a lungful of oxygen and tried to calm himself.

"Something on your mind, Stevie?"

Steve opened his mouth, and Tony could practically see the lecture dancing on his tongue. Bloody lips parted and came back together time and again, until the captain finally surrendered.

"Why… why Bucky?" Steve blinked, his eyes once again moist. "He didn't… He wasn't… why did you…" He swallowed, hanging his head and whispering to the floor. "Why did you make me watch?"

Tony said nothing, watching as the man's shoulders began to shake. He slipped his hands into his pockets, leaning forward slightly and peering into Steve's shadow to confirm the dark droplets were freshly fallen tears. Then he leaned back and pursed his lips, looking upward and considering the ceiling as if the answer would be scrawled somewhere in between the fluorescent lights.

"Because I want you to remember. Every time you look at me, and you feel that hatred burning inside of you, I want you to remember not everyone has that luxury. I want you to remember that some of us have no one to blame for our losses but ourselves, and not because we were careless, but because we cared too much."

Tony heard the restraints move and lowered his gaze, catching the tail end of a headshake as the weeping man offered his weak rebuttal.

"This… this is wrong…"

"Well, I am the villain."

"…this isn't you, Tony…"

Two hands shot forward and seized the tattered shirt, shaking with rage as they pulled on the bloodstained fabric.

"This isn't me? This isn't me?"

Steve inhaled sharply, searching Tony's eyes for any sign that there might be mercy in his future, lips moving in a silent plea for the man to come to his senses.

"How would you know what is and isn't me?" Tony shook him hard, slamming his head back against the wall. "Huh? You never knew me. I was never important enough for you to get to know."

"T-Tony—" Steve pushed against the floor, trying to get himself as far away from danger as he could. "We were friends, Tony, we—"

"Friends don't treat people the way you treated me," the villain hissed.

Steve exhaled sharply and shook his head. "I'm sorry we didn't—" he gasped, "—didn't agree on the Accords, Tony, but—but I did what I could. I t-told you if you ever needed me to c-call, and I—"

Tony pulled Steve away from the wall and slammed him back onto it, screaming with the force of every year he went unheard, every year since the betrayal, every year he looked at that stupid phone and couldn't say a thing to anyone about it.

"I did need you, Rogers!"

Silence.

Tony dragged air down through clenched teeth. "I needed you one time, just one time, Steve, and you weren't there. One time, Steve! Is that too much to ask? You always needed me, and that was why you kept me around. You used what I could give to your advantage until something better came along, but listen—listen to me, Steven Rogers. I never needed you." He shook his head, vaguely aware of blood pooling around the soldier's feet. "I never needed you, and yet I was there for you. I put a roof over your head, and food on your table, and clothes in your closet. I gave you everything you needed, and just about everything you wanted, and I didn't do it because I needed you, Rogers, I did it because I thought we were friends. I thought there was more to us than donning a uniform and clocking in and out together. I thought you cared, because God knows I did."

Steve whimpered—actually whimpered—as he was pushed back against the wall again.

"And the one time I needed you—the one time, Steve, the one time I needed you—you weren't there. You weren't there, and what's worse, you made yourself the enemy."

"B-Bucky…" Steve rasped, his body nearly limp in Tony's hands. "I had to…"

"Don't give me that." Tony glared, lips twisting into a snarl. "That's what gave you away. That was how I figured out you never really knew me, because if you had, you would have known I wouldn't have let them kill Bucky. I was trying to keep your friend alive, I swallowed my pride with Ross, and I begged him to let me have the mission so I could get to Bucky first. Not because I knew he was innocent, because you didn't even try to tell me that, but because I knew he was important to you. I risked everything. I went against the Accords, and I went against my own beliefs to help you, because I was still stupid enough to care."

Steve closed his eyes, body quaking, blood puddle slowly expanding.

"And you stabbed me in the back. You stabbed me in the back, and then you replaced me like an outdated software system. So here we are, Steve."

"Tony—" the man choked, "—Tony, I can't breathe!"

"Are you even listening to me?"

"Tony, please!"

"I love that you call me Tony. Do you expect me to start caring again?"

"Please, I can't…"

Tony let go of the other's shirt and slid his hands down, grabbing the article by its bottom hem and hiking it up as far as he could. Leaning forward, he took a look at the soldier's back and saw the source of his pain, blood, and inability to breathe.

"Oof. They said they broke some ribs, but they never said it was this bad. It must've finally punctured the skin when I pushed you against the wall." Tony let the man go and took a step back, patting the soldier's cheek and giving him a sweet smile. "It's been nice getting reacquainted, even if you weren't paying any attention to me. It feels good to just get it out, you know?"

Steve gasped and heaved, unable or unwilling to speak anymore.

Tony laughed aloud and turned to walk back out of the room, business shoes clicking on the steel floors as he went. It felt good—much better than he expected—to walk away without so much as a backwards glance. It felt like justification. It felt like freedom. It felt like victory.

"I'm…"

Tony slowed to a stop but still refused to look back. "Hmm?"

Steve's voice was so much smaller and weaker than it had been before their conversation started, broken up by pained gasps for air. "I'm… n-not sorry…"

Tony smirked up at the ceiling, giving the silence a moment to linger before continuing towards the door and offering a reply. "No, Steve, you never are."

Steve said nothing, and Tony let the quiet grow and swell until the door clicked shut behind him.

"Alright, boys, you know what to do. Patch him up, and stick him in a proper cell." He started down the hall towards the elevators, laughter rattling his chest as he sauntered along the dim corridor. "Don't let him die. That's his punishment."

There was a small chorus of, 'yes sir,' and then the doors slid shut, leaving the inventor alone with his fractured thoughts.

No, Tony Stark didn't know what the final straw was exactly. But then again, that didn't really matter. Regardless of what had pushed him over the edge, he had fallen to the bottom of the pit long ago, and he was glad he did.

He was never this happy as a hero.