Setting: Arrowverse: Post 2x14 AU. Flashverse: First season AU Marvelverse:About a year post Avengers and the end of CA: The First Avenger. This chapter is pre-CA: TWS.

This chapter is co-authored by srmiller on AO3

Prompt: This grew out of a conversation we had after the episode where Caitlin makes some homebrew for Barry because he can't get drunk. Somehow, it morphed, we wrote it, and then accidentally shelved it.

This takes place not long after Steve and Felicity have met.

For Science

Breathless, Felicity hurried into the S.T.A.R. Labs testing center, leather satchel banging against her hip in time with the clack-clack of her heels on the cement floor.

"Ugh. I did not mean to take so long. The guys had a Thing out in the field and it took forever to sort them out. There is no such thing as idiot-proofing a program. But I'm ready to go out any time you guys..."

She stopped. Caitlin was alone, a white lab coat over her sequinned black dress, her attention on the monitors lining the testing console in front of her.

"Caitlin?" she asked, uncertain. "Where are Barry and Steve?"

The geneticist adjusted a monitor knob with much more care than needed, not quite meeting Felicity's eyes. "In there."

Felicity stepped closer to look through the window on the wall. Usually, the room beyond held only Barry's treadmill and the bulkier pieces of S.T.A.R. Labs' power supply. Now, it was also furnished with two folding chairs, a card table bearing a trayful of glass beakers, and…

Felicity hauled her mouth shut with a snap, glad she'd managed not to drool.

"Caitlin. Not. That I don't want to thank you. For the scenery." She knocked her knuckles against her forehead in an unsuccessful attempt to bring her lust-fogged brain back online, then shook her head. "Something tells me I'm going to regret asking this, but. Why are Barry and Steve sitting in there half-naked and covered in sensors?"

Both men looked up as she spoke, blinking owlishly at the window. Steve's once neatly combed blond hair stood up in hedgehog spikes, as if he'd raked his fingers through it a few times and had forgotten he'd done so. Barry, who looked even worse for wear, gave her a cheery, beery wave, nearly toppling off his chair as he did.

"Hiiiii, F'lic'ty," he called. "We're doin' a science 'speriment!"

Felicity turned on Caitlin, who flushed as she gestured to the bank of monitors on the console, each showing a different graph. "I needed to measure and regulate-"

"I told her we coulda left our shirts on," Steve interjected. He sat upright, shoulders squared, but he stared at Felicity as if focusing required all his concentration and his Brooklyn accent was thick enough to cut. "But she said she hadda use the sensors."

Felicity did a double take, this time not because of the mind-melting display of muscles. Wait. Was Steve -

Diving for the console, she fumbled around until she managed to cut the intercom.

"Caitlin Snow, did you get Steve and Barry drunk?" she demanded. "Why? And how? I didn't even think that was possible."

"Kind of. Actually, sedated. It's supposed to make them sleepy, not drunk." Caitlin winced, holding up a hand as Felicity opened her mouth to speak. "S.H.I.E.L.D. gave us an emergency order for a sedative that works on individuals with accelerated metabolisms. So many metahumans and Enhanced have them. The agents want some way to subdue criminals besides using stun batons or guns."

"Right." Felicity sneaked another look into the testing center. She probably should be jealous Caitlin had figured out a way to get Steve's shirt off before she had, but who was she to argue with the results? "And that explains this"

"I came up with a formula I think will work. Dr. Wells mentioned it to S.H.I.E.L.D., and now they're calling and demanding we give it to them yesterday. And I won't release it until it's been tested." Caitlin brushed back the wave of rich brown hair falling across her forehead, grimacing. "When you were delayed, Dr. Wells suggested asking Captain Rogers, since he has an accelerated metabolism. Captain Rogers agreed to help."

"Of course, he did," Felicity sighed. Steve didn't need a helper; he needed a keeper. Good thing there hadn't been an experimental grenade he could throw himself upon. "You do know he tends to volunteer for things he really, really shouldn't? I mean, it's not like he says no to anything." She caught herself as Caitlin smirked. "I meant. Line of duty. Not. Otherwise."

"Really?" Caitlin asked, all innocence, then relented at Felicity's stare. "Speaking of line of duty, we did secure his shield. He called in to tell his handler he'd be unavailable for a while, too."

"Thank goodness for that," Felicity sighed. "After some of the crazy training games Barry and Oliver came up with sober, I can just imagine Barry deciding they should play Ultimate Frisbee Tag with Steve's shield."

"Way ahead of you." Caitlin rolled her eyes. "Which one of us works with Barry every day?"

"How did Barry get into this mix, anyway?"

"He volunteered to participate since he's got an accelerated metabolism, too. He's off the curve for most metahumans, but Dr. Wells thought more data couldn't hurt. And..." Caitlin coughed a little, "Barry is a bit of a show-off sometimes."

"Maybe not the understatement of the year, but definitely the last few months," Felicity agreed.

A small buzzer sounded beside her, echoing in the testing room. Caitlin clicked a button and spoke into a microphone. "Time for the next."

Felicity jerked back around to the window as Steve and Barry each picked up a beaker and downed the contents. Barry thumped a fist against his chest, wheezing. Steve set the beaker down, his hand steady, but listed sideways in his chair.

"What are they drinking?" she asked.

"Water with a small amount of the sed-oh, no." She broke off and flipped the speaker on again as Barry began talking. Frowning in deep concentration, Steve squinted at him as if Barry had suddenly turned ant size.

"Metagene is so better'n serum. The metagene gave me super speed," Barry jabbed the air with his forefinger for emphasis on each word, spluttering like Daffy Duck on each S. "Wha'd the serum give you?"

"Made me taller." Though Steve spoke carefully, his vowels sounded slushy. He leaned back in his chair, biceps flexing as his hands tightened visibly on the armrests. Plastic squeaked in protest. "An' I got bigger. I was even skinnier'n you when I got it."

Barry reared back in indignation. "Wha' you mean, skinny?" He stood, pointing to his abdomen. "Lightning gave me abs!"

Felicity pinched the bridge of her nose. "Are you done yet? We don't need to see any more of this."

"Oh, I don't know," Caitlin murmured, distracted, watching Barry.


The researcher almost jumped out of her pumps. "Right, we..." her eyes slid back to Barry for a second, then to Steve, then back to Barry. "Right."

"Trust me, I don't think we want to let them go where they're going to go next." When Caitlin shot her a look of disbelief, she added, "Besides, we wouldn't want them staring at us, right? It's male objectifica..." she trailed off, gulping, as Steve stood, looming over Barry. She'd been privileged to see more than her fair share of beautiful half-naked men, but Steve had muscles she hadn't known existed. "Oh."

She didn't notice her mouth was stuck open until Caitlin nudged her.

"Son, you need to calm down," Steve pointed in Barry's general direction, index finger wavering. "There'sh…there's ladies present."

Felicity shook herself. "Okay, definitely time for an intervention."

"Good idea." Caitlin hastily released the security locks on the doors. "I've got enough data and we're going to see some high speed running into walls if we don't, I think."

Wrenching open the door, Felicity took two steps into the room and stopped, coughing, her eyes watering. The place smelled like a combination of a distillery, a month's worth of dirty gym socks and an MIT chemistry department experiment gone seriously wrong. S.H.I.E.L.D. could probably knock the metas out with the smell of that stuff alone.

"So, are you two about finished pickling your livers?" she asked between coughs.

"Hiya, dollface." Steve's stern expression melted into a sweet, goofy smile. His eyes oscillated as he took in her strappy black dress as if he were trying his best not to stare and not succeeding in the slightest. He shifted on his feet and almost fell over before managing to sink back into his seat. "You look. Um. Really. Um. Swell."

Felicity shook her head. All he needed were X's where his pupils were to complete the picture of someone ready to pass out on the floor. But it would be easier to get annoyed with a golden retriever puppy than with that face. She combed his hair back into place with her fingers, smiling at him.

"What am I going to do with you? I leave you alone for three hours and what do you manage to do?" she asked.


Three heads turned to Barry, who nodded like a Flash bobblehead doll.

"I got that part," agreed Felicity. As an aside to Caitlin, she said, "Do you have some place they can sleep it off?"

"I sent Cisco to set up a couple of cots for them." Caitlin frowned, then pulled her phone out of her pocket to send a quick text. "I think I'll have him bring them in here, though."

"You'd better. Between the three of us, we might be able to get Barry out of here, but there's no way I can drag Steve to a bed."

"You don't have to drag me to bed," Steve offered. "I'll go with you."

Even though she knew the double entendre wasn't intentional, Felicity choked on more than the fumes. She didn't dare look at Caitlin but she heard a muffled snicker from the other woman. Before she could respond, the buzzer sounded.

"Wait!" Caitlin exclaimed. "I forgot to turn off the -"

"Challenge round!" Barry yelled, interrupting her. "You giving up, Cap?"

"Hell, no. I could do this all day," Steve informed him.

It wasn't the chemicals making the smell, Felicity decided; it was a compound of sheer stubbornness and testosterone.

"Guys, Caitlin has all the information she needs," she said. "Do you really think this is a good..."

Ignoring her, each man grabbed a beaker and downed the contents, blearily staring each other down as they did. Steve's upper body moved in a slow circle before he leaned back and closed his eyes, the beaker slipping from his lax fingers to the floor. Felicity sighed.

"...idea," she finished.

Barry grinned up at Caitlin. "I wo..."

Felicity and Caitlin leaped forward barely in time to keep him from slumping off the chair.

"Congratulations, Barry," Caitlin gasped. "I'll be sure to remind you of that in an hour when you don't remember what happened."

They had just managed to fold Barry over the table when Cisco coasted in on a flatbed trolley with two cots on it. Seeing the two limp figures, he burst out laughing. "Does this mean what I think it means?"

"If you think testosterone went up against science and science won, yes," Felicity told him.

Cisco sniggered. "Science usually does."

Although Cisco put the cots beside the chairs, by the time the three of them managed to maneuver the two men into something like a prone position, all three of them were panting with effort and sweating. Felicity staggered back a few steps, lifted her hair off the back of her neck and fanned it with her free hand.

"How long is this supposed to last?" she asked.

"No more than half an hour." Shrugging off her lab coat, Caitlin laid it over the table. "I'm sorry. I'm going to have to work on this formula. This was supposed to hit them much faster than it did. I thought they'd be in recovery by the time you got here."

"Yeah, and we're never gonna get a table at the bar if someone doesn't get over there soon," Cisco interjected. "The cab's supposed to be coming for us in a couple of minutes. Why don't you two go on and hold a place for us?"

"I don't want to leave them unattended," Caitlin began, but Felicity could tell she was wavering.

"I'll stay," Cisco volunteered. Too quickly. Warning bells rang in the back of Felicity's mind. From Caitlin's frown, the other woman was equally suspicious, but she shrugged, acquiescing.

"All right, I guess."

"Sa-weeeeet!" Cisco carolled, rubbing his hands together. "This is gonna be awesome."

"Wait, what is?" Felicity demanded.

Cisco produced a marker from his shirt pocket and wiggled it between his fingers. "Dude, what do you think? I'm gonna draw a picture on both their faces and Instagram it! Captain America and the Flash? This is gold."

"NO!" Felicity and Caitlin chorused.

"Awww, I was just gonna do word balloons," Cisco whined. "Even I wouldn't draw a dick picture on Captain America. And I wasn't going to say who they were in the caption."

"But you would draw one on Barry?" Caitlin huffed.

"Hey." Cisco shrugged. "What's a dick picture between bros?"

"Twenty-six going on twelve," Felicity sighed. "Cisco, if you do anything, I will find the most embarrassing picture you've had taken, ever and spread it everywhere."

"They used to give him swirlies in school," Caitlin mused. "I bet there's a picture of that somewhere. What do you bet, Felicity?"

"If it's on the Internet, I'll find it." Felicity promised, crossing her arms and glaring at Cisco.

"You wouldn't." Cisco glanced back and forth between the two women, then sighed, tucking the marker back into his shirt pocket. "Fine. I'll go get the table and you guys can wait here."

"Oh, no. You volunteered. You stay," Caitlin said firmly.

Leaving Cisco grumbling behind them, the two women went outside.

"Even if it did kind of mess with the evening plans, I guess I should thank you. I've been wondering what Steve would look like shirtless," Felicity commented.

"Yeah." Caitlin nibbled her lower lip, lost in thought. " You know, for someone without much muscle mass, I'm always surprised he has so much definition."

Not much muscle mass? From what Felicity had just seen, when it came to muscles, Steve had more mass than Jupiter. Then the other shoe dropped.

"You know, if you wanted to get Barry's shirt off, there are easier ways," she teased.

"Who says I did?" Caitlin protested, though a betraying flush crept up her cheeks.

"Just saying, other than Steve, these guys do pretty well stripping down on their own. Believe me," Felicity sighed, raising a hand to wave at the cab pulling into the parking lot. "Shirtless. All the time. Shirtless."