Title and opening quote from Talin Tahajian's our youth at night. For the trope bingo square transformations. Thanks to A for help, all mistakes mine.


The world
usually smells like it's dying
but it's the same smell
as those chlorine summer
nights so you learn
to fall in love with it.

After Tony and Pepper broke up, after Tony made sure that all the idiots on the raft were given pardons and let loose, he ran into Natasha while she was undercover.

It was impressive and not surprising how effective she was at disappearing. He knew Natasha fairly well, but he nearly didn't recognize her until she touched her neck and Tony remembered that gesture from her Natalie days. He didn't think it was an authentic Natasha gesture, he thought she was playing a part similar to Natalie.

Tony didn't do undercover, he was at the bar as himself and had already been Instagrammed and Snapchatted by at least six people. So he let Natasha do her work and he sat in VIP with Happy and talked to three fashion models. One of them was a fun little spitfire but mostly Tony was thinking about how much she reminded him of Pepper. After he left, he texted the last number he had for Natasha just to say hello. Natasha was a fun slow burning spitfire who would knife him without any warning. He would probably deserve it.

Natasha showed up at his new place in Manhattan the next morning. He didn't ask how she eluded security. He wondered for a moment if she'd even had to, it's not like he'd ever programmed anything to keep her out. That was probably an oversight.

"Who are you working for now?" Tony didn't look up from his simulations. He was trying to create the holy grail, the easy to use energy source, the one that cost nothing. He had a lot of ideas but he wanted it cheap and he wanted to be able to send it everywhere. He kept hoping someone else would make it work but it hadn't happened yet.

Natasha said, "You think I'm working? Maybe I like to date without giving away who I am."

"Sure, that's logical," Tony said. "Because you're very focused on dating, Little social butterfly spider."

"Why do you care?"

"I thought we were friends," Tony said. "Weren't we like bosom buddies? You were on my 'team.' Until you weren't, of course. But I get it."

"We're not talking about this anymore," Natasha said. She sat down next to him. "I heard from a friend of a friend that there's something that might need attention happening around here."

"I really hope they gave you more detail than that," Tony said. "Are you here because you need help? From moi?"

"Maybe now I don't," she said, getting up. "I'll find another billionaire."

"Try those Walmart kids, I've met them and they're not that smart. Not as smart as me, anyway."

"I bet they're smarter than you," Natasha said. She smiled at him, like she meant to be charming. He didn't like that smile at all.

"What, specifically, do you need? Did you go to that bar so I would see you? I bet you did," Tony said. "You're truly amazing."

She just kept looking at him steadily.

He said, "Fine. Sure. I'm a little banged up, but I have some time left."

First he updated her suit and weapons. He didn't touch the one incredible blade thing Natasha got in Wakanda, it was too good to do anything but admire. The people in Wakanda were incredibly impressive, definitely geniuses. Maybe she'd let him take it apart someday, but until then she needed it. He brought his upgraded suit, the one that helped him feel slightly younger than 48.

She picked him up in a very expensive car and took him to an abandoned building. Abandoned skyscraper, actually. Tony recognized the building vaguely, it was still unstable from the Chitauri invasion. Litigation had stopped everyone involved from being able to tear the damn thing down for all these years. Tony had offered to just buy it once, but Pepper had just said, "I wish that would work." The frustration in her voice made him avoid any and all details.

"This building is unsafe, you should have a hard hat," he said.

Natasha ignored him and went inside. After getting his suit on, Tony followed her. "Okay if I use a flashlight or something else? Let there be light?"

She said, "Go for it."

The floor they entered had been the lobby. All the furniture and more than a few fixtures were gone. A plant was growing out of its pot, onto the floor and spreading out. It was weird. Tony looked again and Friday popped up a deeper view. The roots had shattered the bottom of the pot and the new tendrils were breaking apart the tiles, burrowing into the concrete. "Did you bring me here because of the plant?"

"The plant is just one thing. Look up." Natasha was already walking towards the stairs.

The ceiling had spreading plants, too, running along and heading towards the walls. He followed her to the stairs. "It feels ridiculous just clomping up these stairs," he said.

"Why are you?" Natasha looked over her shoulder with a smile.

"You're leading, I'm following. Frankly, I'm a little scared of what's ahead of us. It must have been something if you're worried enough to call me," Tony said.

"I'm not worried," Natasha said.

He was inordinately proud that he could tell she was lying. Maybe she was being obvious on purpose. He said, "You're lying."

Natasha sighed which was probably a yes. They'd reached the second floor. It was largely conference rooms with open doors and a carpet. He paused and looked closer. It was a carpet of a plant, a spider plant he thought and Friday confirmed. A regular ordinary spider plant. "Is every floor like this?"

"Every floor except the 12th, 16th and 19th. I think there just weren't plants on those floors. There will be soon enough," Natasha said.

"Is this some kind of bad guy thing? This is unnatural growth. Is it Chitauri?"

"I think there's bad people involved somewhere in this process, it is unnatural, and it's not Chitauri. The building is unstable because one of the larger aliens flicked its tail and took out most of the 14th floor. No dead aliens left here, no weapons, nothing," Natasha said. "The plants just grow, they're not predatory. They won't grow into your suit unless you stood very still for months. I think," Natasha said.

"I'm not testing that," Tony said. He used his scanners to try to trace where the plants started, where they were going. He picked up one of the leaves and broke it off. Nothing regrew, which made Tony very grateful. He crushed it with his glove and had Friday look at it down to the molecular level. "It's just a plant. No out of the ordinary processes or chemicals present."

Natasha looked at him calmly.

"This is freaking me out, thanks for bringing me here," Tony said. "Let's get out of here."

Natasha said, "I wanted your help to rule some things out, I can take it from here."

"I can't leave you alone with the magic office plants," Tony said.

Natasha just looked at him. Tony said, "I know I'm not a finesse player generally, but I can investigate."

Natasha smiled. Tony said, "There are things I can do."

She rolled her eyes, but to Tony it seemed like an affectionate roll of the eyes. "Fine," she said. "You're so eager."

"Did you do all this to make me get involved?"

"You overestimate my manipulations," Natasha said. "Maybe I just want to spend time with you."

Still she let him collect more samples and went with him to one of his labs. He also took environmental samples and then had Friday prepare results for him. Natasha was an able lab assistant, even if she was about as chatty as DUM-E. He had the impression she was enjoying herself. Maybe she even liked his company.

They still didn't find anything. Natasha sat on a stool with her legs crossed, regarding him serenely. He wished just once he could see through her multiple layers to what was actually going on, whether he was right that she possibly liked him. "I think it's magic," she said.

"I never know what's about to come out of your mouth," Tony said.

"I think it is," Natasha said. "You've heard of it."

Tony sighed. "I assume you mean something more than Criss Angel and fast moving hands?"

"You know the magic I mean. Do you have any contacts or should I move on?"

"To someone who knows magic?" Tony tried not to laugh at her. "Don't you know anyone? Because most of the people I know deal in actual concrete facts that can be explained and replicated in a lab."

"Like a portal in the sky?"

"Ask Jane Foster, there's science there," Tony said.

"Maybe magic is just science so advanced we don't know yet how to replicate it in a lab," Natasha said. She had a faint smile.

Tony shook his head. "What do you want me to do now? You've hooked me on the mystery, just tell me what you want me to do next?"

"Take me to a party so we can meet someone who knows something about magic," Natasha said. "Dress nicely."

There were very few elite echelons of society Tony hadn't wandered around in. Even at Natasha's super secret underground party with strange glowing orbs, he recognized a few people and waved at them. They even smiled back at him. He looked at the orbs and put on his glasses to see what was making that thing work. It was unhelpful and frustrating. He wanted to figure it out and he couldn't even find an angle to approach it from.

Natasha pulled on his hand. "Sweetheart, stop staring."

He took off his glasses and glared at her. She kept smiling. She was wearing an amazing wig and this surprisingly alluring lavender lipstick. He was under the impression she was pretending to be his girlfriend and trying to hide who she really was.

His impression was confirmed when she pushed forward and kissed him. He held her waist, not sure how far she wanted him to go. She pulled him closer and opened her mouth. So he guessed he could go that far, or she really needed to hide her face. He let himself be used.

She moved back and wiped his lips with her fingers. "Maybe I wanted purple haze look," Tony said. "I actually had a David Bowie space pirate look going when I was in my twenties. For at least a week. Rhodey has pictures, you should ask him."

"Fascinating," she said. Her voice had multiple tones, he was always so impressed she could do that. She maybe sounded like a trophy girlfriend, agreeing with whatever he said, she maybe sounded stupid, trying to participate in a conversation she didn't know anything about. He could hear that sweet sound of contempt reserved just for him under everything. It was heartwarming.

She started talking to someone Tony didn't recognize and he saw her bring out her phone and show a picture. He tried to listen or lip read but neither was working. The acoustics in this underground space were extraordinary. He knew how they made that part work. It was definitely not magic.

Natasha came back to him and said, "Time to go, honey."

"Okay, Buttercup." In the car, Natasha took off her wig and shook her hair out. He said, "Do you need any more, or is everything settled?"

"I think it's good," she said. "I'll let you know tomorrow since you're hooked." She reached over and rubbed his thigh. He was very grateful he'd gotten a driver for tonight.

He put his hand over hers. "Not that I'm not interested, because I am and also single for the first time in years, but I wonder if -" He could not figure out how to finish that sentence without being insulting or possibly stupid.

"I enjoy your company," she said. "I appreciate that you didn't take advantage of the situation."

"But now I should?" He made sure the privacy shield was up. "I'm happy to, of course."

"Of course," she said, smiling.

She shifted over so she was straddling his lap. She reached around his neck, undoing his tie. He touched her thighs and then pushed her skirt up. She had the softest skin, even as he felt the tiniest scars and longer ones. He was incredibly turned on by her rapt attention, her sure hands opening his shirt. She shuffled a little forward, almost awkwardly. He wondered if that was a plan or part of what she did, then he decided it was really her. He was almost positive she simply wanted to have sex with him.

He pushed her underwear to one side so he could touch her, get her wet, push his fingers inside her. Her head rolled back just a little and she bit her lip. Then she kissed him, more passionately than at magic orb land, and unzipped his pants to get at his penis. She had a strong grip.

She said, "Do you have any STDs?"

"It's so sexy when women ask that," Tony said. "I mean it, it's a turn on. Because I get to say no, I don't. Less sexy, how about you?"

"Clean as a whistle," she said. "Look at us." She kissed him again and shifted on his fingers. She said, "Fuck me."

"I already am," he said, pushing up into her tight tight vagina with three fingers.

She glared at him and then smiled. She pulled his hand away and guided his penis inside her. She moved again so he could get in deep. He pulled on her dress to get her closer, she moved her hips in a way that left him breathless. He tugged harder, thrusting up into her. He closed his eyes because it seemed like the only way he could inhale. He opened his eyes again so he could watch her. His pants were going to ruined, he thought, smiling.

She came first, grinding down on his dick. Then she leaned forward and bit at his neck, he came loudly.

She got off him and pulled her dress down. She said, "You can't wear those pants out of this car."

"Sounds like you're gloating," he said. "You want them as a souvenir? They're very expensive." He took off his shoes and then his pants and underwear. Naturally, it was his car, so he had clothes stashed in a pouch under his seat.

"You're too rich for your own good," Natasha said. "I assume you have a spare set for the women you fuck in this car?"

He shrugged. "I do, but it's all Pepper's size."

Natasha had a soft smile. "That's sweet, sort of. I could use some underwear."

He handed her a pair. She took her wet underwear and balled it up with Tony's discarded clothes. She said, "What poor Stark employee has to gather up your, uh, laundry?"

He smiled. "I do, in this case. Put it in the messenger bag I'm about to carry out of here. Are you getting out here, too?"

She looked almost tentative. She said, "Do you want me to?"

"Of course," he said automatically. He did want her to come up.

They had sex again, this time on his bed. This time he was on his back and she was still on top and it was incredibly hot. After, he played with her hair as she fell asleep.

In the morning, she was gone and he wasn't surprised. He went to his lab and thought about his holy grail again. Easy energy, everyone could have it.

Natasha showed up at lunchtime. She was wearing jeans and a bright Pittsburgh Pirates t-shirt. He said, "Nice shirt."

"I was living there for a few weeks," Natasha said. "They were filming a series about serial killers."

"And you were acting in it? Should I tune in? Or were you consulting?"

"I was a dialect coach," Natasha said. "Sometimes I like to explore alternate career choices."

"What dialects?"

"Talking like an American," Natasha said. "Do you want to know about the plants?"

"Of course I do," Tony said. "Please, please tell me."

"I can tell you're being sarcastic," Natasha said. "But anyway, it was magic. I found the right guy, it turns out some irresponsible, uh, the equivalent of teenage delinquents have been using the building to goof off. Which leaves traces and makes plants grow, apparently. It's not much of an explanation, but it's true."

Tony nodded. "That's ridiculous. Magic is ridiculous. I'll accept it, but it's ridiculous."

She stepped closer. He said, "Ridiculous."

"Are you going to keep saying that word?"

"I feel like I'm stuck in a loop, maybe we can fix that somehow, you could do something to break my concentration," Tony said.

"That's a horrible pick up line," Natasha said.

"I was trying for one you hadn't heard before," Tony said.

"I actually have," Natasha said. "But it's been good to see you again. I mean it."