On the eighth day after the world didn't end, Bruce comes into the lab and it's different. Tony senses it immediately. Something about the way Bruce moves: a little more purposefully. A little quicker.

"What's up?" Tony pushes his safety glasses up onto his head.

Shift of brown eyes to the left. "I have to go up to Westchester for the day," Bruce says. "Wanted to let you know."

Tony replaces the glasses on the bridge of his nose and picks up a torch. "What for?" he says, and he's trying to sound indifferent but it's hard. He knows, every second, that there's a chance Bruce will leave. He's got no ties anywhere, no family, no significant possessions. Tony knows this, knows Bruce owes him no debt, has given Bruce no real reason to stay. But still. He's started to think of Bruce as his, and especially now, after the thing with Pepper, the idea of his departure makes Tony feel unsettled and irritable.

"Just...a meeting." Bruce shrugs his duffel bag a little higher on his shoulder. "I'll be back tonight."

"Okay." Tony turns the torch on, holds it against solder and metal, pulls back when it gets hot enough. "Take a car."

Bruce chuckles. "I know you probably didn't notice the difference, but S.H.I.E.L.D. didn't hire me pro bono. I can handle getting a rental car."

"Yeah." Tony frowns at the component: messy job. He might have to rework this one. "But why do it if you don't have to?"

In his peripheral vision, Tony sees Bruce hold up a finger. "I should say," he corrects, "I can handle getting a rental car that isn't worth two hundred grand."

"They're not all two hundred grand," Tony says, not looking up from his wedge of metal and wire. "Some of them are five hundred grand."

"I'm afraid you put too much faith in my driving ability," Bruce says.

"I trust you with anything in this building," Tony says, a little too forcefully. "Fuck." He left the heat near the solder too long; it's flashed out the other side. Now he really will have to redo the piece.

"You okay?" Bruce starts forward. Stops.

"Fine," Tony says shortly. "'Bye."

"See you when I get back," Bruce says, and Tony doesn't look up until he hears the lab door open and close.

As soon as Bruce is gone, Tony picks up the component with one gloved hand and flings it across the room. It hits the wall with a clang, leaving a black mark.

"Fuck," he says again.

He's antsy for the rest of the morning, unable to work on one project for more than a few minutes at a time. Finally he gives up. "JARVIS," he says.

"Yes, sir?"

"Did Bruce take a car?"

"He did not, sir." JARVIS's voice is dryly amused. "The exterior security cameras caught him getting into a cab."

"Course." Tony exhales hard. Because he wants to know - really, really, really wants to know - what Bruce is doing in Westchester.

"JARVIS?"

"Yes, sir."

"Do we still have keystroke logging on all the computers in the building?"

A pause. "Yes, sir."

"Can we - "

"Sir, if I may interrupt." JARVIS sounds a little more forceful than he usually does.

"Looks like you're going to anyway," Tony says crossly.

"I would advise, sir, that you carefully consider how the tools available to you are used," JARVIS says. "In order to avoid any...regrettable...decisions."

Tony knows exactly what JARVIS means by that. Right. Called out by his own damn AI. How is that not a design flaw, exactly?

"Forget it," he mutters. He wouldn't have broken into Bruce's email anyway. He just wanted to know that he could. If it got to that.

He's not sure why it matters so much, anyway. It's not like Bruce belongs to him, even though it kind of feels that way sometimes. It's not like it makes a difference if Bruce stays or leaves.

Except it kind of does.

Tony is used to getting whatever he wants; hell, he's used to having it before he knows he wants it. People throw themselves at him, trying to impress him, trying to get him to pay attention. It's always been that way.

Bruce, though.

Bruce is...what is he, exactly?

Tony is not at all, not in the least, not in any way shape or form accustomed to looking up to anyone. He's the best and brightest, after all, and he's proved it to himself and everyone else over and over and over again. But Bruce - Bruce is the only person Tony has ever met who might outstrip him in the intelligence department.

He's also the only person Tony's had trouble understanding.

The brainiac thing doesn't bother Tony at all. Tony admires Bruce's intelligence - more than admires, he's cowed, he's fucking awed by it - and God it's so incredibly sexy hearing him talk about particle physics and string theory, he gets butterfly-stomach just thinking about all the brains behind that enigmatic little smirk. He wants to dive into Bruce's head and just...roll around in all the smart for a while.

The thing that really gets Tony is that he can't figure out what makes Bruce tick. It's more than the anger management - he knows that Bruce has to keep the green guy under wraps, and he gets that, he does. But he can't for the life of him figure out what Bruce likes, what he hates, what he wants.

For the past eight days, he's been trying every trick he knows (and he knows a lot, although admittedly he almost never has to use them) to elicit some kind, any kind, of response. And maybe it's because he can't get a rise out of Bruce, and maybe he's just tailspinning from the Pepper thing, but it's driving him absolutely fucking nuts. It's the same reaction every time, whether he's whispering unnecessarily close to Bruce's ear or giving him an impromptu shoulder massage or flat-out grabbing his ass: a shake of Bruce's head, a small smile, and a rueful sigh.

Two days ago he got into Bruce's face, close enough that their noses were touching, and adopted his best Hannibal Lecter voice. "Yes or no?" he growled, and Bruce just laughed and shook his head and turned away.

He'd never really understood that whole "wanting what you can't have" thing, because before, there was literally nothing he couldn't have. He gets it now. And it's making him crazy.

He doesn't know what to do with himself. Bruce is gone and he can't talk to Pepper and he feels weird and unbalanced and shiftless. He can't focus on anything and he keeps thinking of Bruce's hands, for some reason, those oversized mitts that look like they should be palming a basketball instead of manipulating a one-milliliter pipette.

Finally he gets fed up with himself - grabs his hair and moans "Christ, Tony" in sheer exasperation - and decides to take the Mark VII for the initial calibration run he meant to have done two weeks ago. He flies into the lower atmosphere and his temperature and pressure and humidity sensors start to light up.

"Altimeter/environment sensors calibrated," JARVIS says after a moment. "Additional altitude not required," and Tony turns and dives back toward the earth.

The thing with Pepper threw him, and Bruce was there, so of course - of course - he hid in Bruce's company. It makes sense. It doesn't mean anything, other than that he pinged off of Pepper and happened to collide with Bruce.

He needs to get over it, because this is fucking ridiculous. He splashes into the ocean, dodging neatly around an enormous, deep-swimming something (JARVIS helpfully identifies it as a whale shark), and powers straight down until he approaches the bottom.

"JARVIS," he says, "how much more can we take?"

"Pressure sensors are nearly finished calibrating, sir." A fifteen-second pause. "Calibrated. You are at seventy-five percent pressure capacity, sir, and a depth of 147 meters."

"Good enough for now." Tony might push for the red zone if he was feeling more focused, but instead he jackknifes and shoots back toward the surface.

Bruce walked into his life ten days ago and fucked everything all to hell the second he shook Tony's hand. Goddamn it. Just...goddamn it. Because now he's all ridiculous and mopey and needy and if there's one thing Tony Stark definitely is not, it's needy.

And then, of course, there's Pepper.

Pepper. Pepper who laid eyes on Bruce for all of two seconds and changed. No. Changed isn't the right word. Transformed. Morphed. Neither Bruce nor Tony had said a word to her and she was already different. She looked the same, she acted the same - started to hug Bruce, then fell all over herself apologizing when Tony stopped her and explained the unexpected-touching thing - but she wasn't the same. Tony only suspected it until he had Bruce settled into the guest bed and went to his room - their room - and then he knew it. Because she wasn't there.

He went down to her apartment and the door wasn't locked and she was sitting at the kitchen counter and she was crying.

He was at her side at once, hovering, asking What's wrong and What did I do and apologizing for all the things he could think of, because Pepper hardly ever cried and when she did it was almost always his fault. She pushed him away and stood up, still crying but not sobbing, and she still sounded like herself when she spoke. Her back was to him so he couldn't see her expression, but she turned her head enough that he saw the tears tracking down her cheeks.

When he asked what was wrong for probably the fortieth time, she just said "I'm sad."

Why, Pepper, for God's sake will you please just explain to me why, why are you so sad, what did I do, what did I do.

She shook her head. "You did nothing, Tony," she said, "this time you did absolutely nothing."

He threw his hands in the air. "Then Jesus Christ Pepper, why are you crying?"

"Because," she said, and he heard her breath catch but her voice stayed steady, "because we're done, Tony."

"What the hell are you talking about?" He came around the couch, put a hand on her shoulder, and she pushed it away. "Are you breaking up with me? If you are, I want my letterman jacket back. No." He started to pace. "I'm sorry. Seriously, Pepper. What are you talking about?"

"You need me, Tony," she said, still in that weirdly calm voice.

"No shit I need you." He came around in front of her, took her hands, ducked his head to try to meet her eyes when she looked away. "I'm completely useless without you, I can't take a piss in the morning without you to tell me which way the bathroom is, I'm sorry, that was crass, I can't help it. Yes." He tightened his hands when she tried to pull away. "I need you. I absolutely need you. I also need you to stop crying because I am as confused as a German on Harajuku Street right now."

She looked at him then. "Will you be quiet and listen to me?"

He dropped his gaze. "I'm sorry."

She took a deep breath, gently extracted her hands from his. Reached up and cupped his face.

"You need me," she said again. "You're with me because you need me, but I can't match you, Tony. I'm smart and capable, but I'm nowhere near where you are. I can't keep up."

He pulled away from her, waved off her words, heard the truth and refuted it: "I don't know what you're talking about, catching up," he said, turning his back on her. "There's no catching up, we're a team, Pepper, there's a U in team and it's spelled like Pepper. You and me. I can't function without you."

"You can't function without me," Pepper acknowledged. "But, Tony, I can function without you."

He put both hands on the bar, leaned into it, closed his eyes. "What are you saying, Pepper."

"I'm saying that I will always be here for you, because you need me. But I can't - " She paused. "I can't need you."

"Why?" He stared at her, desperate now, unsteady; he's just saved the world, isn't he supposed to get the girl, not lose her? "Why the fuck not?"

"Because." She folded her hands in front of her (and he thought Bruce does that and pushed it back down) and closed her eyes, and when she opened them again they were even and calm. "Because you're going to find someone, Tony, that you don't need. That you want. And I want that for you."

And then she kissed him lightly on the lips, and took him by the shoulders, and turned him toward the door.

"Get out of here," she said, and suddenly she was Pepper again. When he looked at her, she smiled. It wasn't a real smile, but that wasn't what mattered.

"Pepper - " he said, and she shook her head.

"Not now, Tony." Firmer this time. "Some other time we'll talk about it. I can't right now, I don't know when I'll be able to, but we will. Okay?"

And what choice did he have, now that she was Pepper again, his Pepper, with her questions-that-aren't-questions and no-argument tone? What choice but to go?

"Pepper," he said desperately. "I love you."

Her eyes filled again, but she kept walking. Propelling him.

"I know," she said, and closed the door behind him.

They didn't talk about it again, still haven't talked about it, and after that night it was like they had never happened. She's at his elbow just like always, smiling and joking and keeping him together, and he's still bewildered. He tried talking to her twice and both times she changed the subject. The second time he pushed it, and in response he got a firm "No, Tony" and her back as she walked away.

Tony flies as far as Montreal before looping back toward home. He detours over Westchester and actually drops altitude before changing his mind and shooting up higher than before. This is stupid, this attachment to Bruce, stupid and illogical and obviously a reaction to Pepper breaking up with him.

He brought it up the day after it happened, when Bruce was at one workbench and he was at the other. "Pepper left me," he said.

Bruce didn't look up, but his eyebrows twitched toward his hairline. "Left you?" he said.

"Not really left," Tony clarified. "She's still here. Just not...with me."

"Hm." Bruce bent down, bringing his face closer to the circuit board he was assembling. And then...nothing.

Tony didn't really know what to say after that. So he went back to work, and didn't bring it up again. He's still kicking himself about mentioning it because what did he expect? A pity party? Bruce's shoulder to cry on?

Tony starts to spiral down toward his landing pad. No Pepper. No Bruce. Just his huge, empty tower, echoing with a thousand things he should have said.

Fuck.

He really needs a drink.