A/N: This is for Tumblr user thatgirlinredandgold in celebration of the FitzSimmons Secret Santa exchange. I really hope you like the story - I kind of interpreted the prompt in a very broad way, but it was still great fun to write. :)

Jemma's heart rate steadily increased as she attempted to navigate through the crowded Playground hallway. Perhaps it was wrong of her to worry prematurely. Perhaps the jolt of panic she'd experienced at receiving the urgent message didn't actually mean anything bad. But after having spent months in the heart of HYDRA's laboratories, Jemma had learned to adopt worry and dread as part of her daily routine. And with all the excitement of the past few days (seeing Coulson struggle at the edge of mental stability, as well as discovering the true nature of the strange symbols), Jemma knew her worry wasn't entirely unfounded.

By the time she reached the Bus's cargo hold, only a few others had arrived before her. "What's going on?" she asked anxiously, a bit annoyed with herself that she was nearly out of breath already. "Has something happened?"

Fitz and Hunter looked just about as clueless as she was, but Trip grinned over at her. "We've got a mission," he said.

As much as she wanted to feel comforted by his words, Jemma could still hear her heart pounding loudly in her chest. "Is it the city?" she asked. "Have we got a lead on where it could be located?"

"Potentially."

Jemma spun around to see Coulson making his way up the cargo ramp, a few manila folders held in his hands. He wasted no time in diving into the briefing, even though it was still just the four of them gathered together.

"We've received word from one of our contacts that in exactly…" Coulson lifted his arm to inspect his watch. "Three hours and four minutes, we'll have a window of opportunity that could potentially put us in the lead at finding this thing. But we have to move quickly."

He stepped forward and handed one of the folders to Hunter. "Here's your target," he explained. "Read it, study it, memorize as much of it as you can in the short timeframe we have. Most of our success tonight is gonna depend on you."

Hunter briefly glanced inside the file. "I'm pretty good with faces, sir," he reasoned with a shrug, closing the cover after a few seconds. "Shouldn't be too hard to take him out."

Coulson's expression remained unchanged. "That's nice," he said dryly. "Only I'd appreciate it if you didn't cross off one of our most valuable sources, actually."

Hunter's brow furrowed in confusion, his confident demeanor faltering somewhat. "Um…I don't think I under-"

"Your mission tonight is information-based, only," Coulson interrupted. "I'll need you to approach the target, get him talking. Preferably away from the wife, if you can. He's military, but he likes his port almost as much as he likes to brag, so I'm sure you two can find something to talk about." In Jemma's peripheral vision, she noticed a smirk on Trip's face as Coulson continued. "Whatever you do, make sure you get the name of his supervisor and when the inspection's supposed to happen. Got it?"

Hunter was examining the file again. "Sure, sure," he said dismissively. "So it's undercover then?"

Coulson nodded. "A gala event, held at a country club just outside the city tonight," he explained. "Our target and his wife were last-minute additions to the guest list. If everything goes smoothly, you should be out of there before the first course."

"Let me guess," Hunter replied in a sarcastic voice. "Bobbi's coming along, too."

"No, I need Agent Morse to stay here and get started on cracking our newest visitor," Coulson shook his head. Jemma froze in place, withholding a shudder. She hadn't forgotten that Bakshi was in their basement, but the prospect still managed to give her the chills. "If we want to get ahead of HYDRA, we've gotta know more about what they're planning," Coulson finished.

Hunter still seemed puzzled. "So I'll be going in alone?"

"No," Coulson scoffed, looking horrified by the suggestion. "God, no. You might as well go in with a target on your back. No, this thing is invitation only, so you'll need someone who actually knows what they're talking about." He opened one of the remaining folders and held up two small squares engraved with golden writing. Jemma barely had time to read the event title, but her stomach still dropped to the floor as she realized what Coulson was going to say next. "Which is why Agent Simmons will be going in with you."

Jemma saw Fitz's shoulders tense up, and Hunter had his mouth open in protest. But Jemma spoke up before anyone else had a chance to. "Sir, I'm not entirely certain if that's the best-"

"It's not up for debate, Simmons," Coulson told her, but his voice was gentle. "You'll be fine. As far as I know, it's just a gala honoring achievements in the biosciences. No HYDRA, and you'll be in and out before you know it."

Jemma had a thousand other arguments as to why she should not be given this particular assignment, but she knew from experience that trying to argue with Coulson would get her nowhere. Instead she cast her eyes downward and gave him a small nod. "Yes, sir."

There was a short pause before Hunter held up a hand. "Wait, hang on," he said, alarm flashing across his face. "Look, I'm not questioning your judgment or whatever, but maybe we can stop to think about this for a second?" He turned his head to look at Jemma. "I'm sure you're…brilliant at what you do, a lovely, chipper person and all that. But Bobbi told me about what happened at HYDRA." Hunter faced Coulson again. "She can't lie."

Jemma briefly thought about protesting, but deep down she knew he was right. (And she was also momentarily thrown by the fact that he'd used the word "chipper" to describe her. What was that all about?) Thankfully Coulson took the burden of responding.

"I actually don't need her to," he said coldly. "She's got two PhDs in fields that you've never even heard of, and a work discipline that would probably scare the living hell out of you. She doesn't have to lie. So I'd be a bit more careful if I were you, because she's your real ticket in there tonight, and your only hope at not sticking out like a sore thumb. The lying part will be your job. Are you gonna be okay with that, or should I go ask Koenig if he wants to go instead?"

Hunter looked more annoyed by Coulson's reprimand than anything else. "Yeah, yeah," he sighed, folding his arms.

"Good," Coulson replied curtly, and when Hunter wasn't looking, he gave Jemma a small smile. It didn't make her feel any better about going undercover again, or about going on her first mission since she'd returned from HYDRA. But it warmed her heart to know that despite her terrible track record in these kinds of circumstances, Coulson still had unwavering faith in her ability.

Just then, a loud clanking sound echoed throughout the hold. Skye came rushing into the space, dragging a metal clothing rack up the ramp. Trip quickly went over to help, and pushed the assortment of ballroom dresses and tuxedos up the remaining stretch of the incline. Skye stepped over to the side to let him pass and heaved a deep sigh, brushing the hair out of her face before she reached into her bag. She had two passports in her hands when she approached Jemma and Hunter.

"Here are your covers," she told them, checking the identifications before handing them over. "The security shouldn't be that bad, so you shouldn't have any trouble using those to get in."

"I guess I should've been more clear," Coulson said apologetically, probably noticing Jemma's panicked expression. "You'll have to lie about your identity, Simmons. You think you can handle a false name?"

Jemma swallowed back her irrational dread. "Yes, of course, sir," she assured him, but it was accompanied by a nervous laugh as she stared at her new identification. "It's just a name, yeah? I can do that. Yes, of course I can do that."

After she'd committed the name to memory, Jemma glanced up again to see that even those that hadn't protested earlier looked apprehensive now. She rolled her eyes, even though she was more irritated with herself than the rest of them. "I can handle it," she promised.

Skye stepped closer, addressing both her and Hunter. "Okay, so you guys are newlyweds, but you're kind of in the final stretch of the honeymoon stage, so you don't have to be all over each other or anything. Just like a hand on her back, touching his arm, laughing because you think the other is so damn hilarious, that kinda stuff." Jemma hung onto her every word, knowing she'd need Skye's voice in her head if she was going to have any chance of being successful later. The desperation was probably written plainly on her face, because Skye seemed to address her more than Hunter as she continued.

"Simmons," she went on. "You kept your maiden name because it's twenty fourteen and you've already made a name for yourself as a successful biochemist. Plus, your father recently passed away, so you'd like to keep his name attached to your own as a way to honor him. Your husband doesn't care because he's not a douche." Jemma heard Hunter scoff quietly next to her, but Skye ignored him. "You're both from the UK, but you live in America right now. Hunter, you like it here and kind of want to settle down. Simmons, you're a bit more torn, because on the one hand your work is mostly in this country, but you also know your mom is in a fragile state after losing your dad. You guys haven't argued about it yet, because you're both trying to keep that honeymoon feeling alive. But there's just a little tension between the two of you. It's barely noticeable, though, so I wouldn't worry about it. And anyway you both have plenty of time to figure out all that stuff later."

"Bloody hell," Hunter murmured. "Do we really need all this?"

Skye gave Jemma a reassuring smile before looking at Hunter. "Simmons does better with a back story."

"Well…" Coulson winced, and Jemma knew he was probably remembering the disastrous incident on the train. "I wouldn't say…that's not…okay," he said, waving a hand dismissively. "Thank you, Skye. I'll take it from here."

Skye simply shrugged and turned so that the five of them were lined up in front of Coulson. Jemma tried to sneak a glance over at Fitz, realizing he hadn't said a word since she'd walked on the plane. But he was staring off into space.

"Like I said, we have a very short window here," Coulson told them. "But if everyone sticks to the plan, we should be okay. Hunter and Simmons will be the only ones attending the actual event, but the rest of us will still be on-site. So it's formal attire for everyone, just in case. When we arrive, I'll enter the premises first and head over to the west wing of the building, where I'll be meeting with a few officials on S.H.I.E.L.D. business. I'll be on the comms, but I probably won't be available to talk, so Fitz and Skye will be in charge of monitoring security and making sure Hunter and Simmons enter and exit without any trouble. Trip will provide tactical support as necessary. Any questions?"

Hunter lazily raised up his hand. "Yeah, I've got quite a few, actually. But my main concern right now is, um…you said this thing's in three hours? How the hell are we gonna get there on time?"

"You know, Hunter, weirdly enough, that's the first thing you've said today that hasn't made me want to punch you in the face," Coulson replied. "We're gonna get there on time because Agent Triplett here will make sure we get there on time." He nodded to Trip. "Wheels up in thirty?"

Trip gave Coulson a wide smile. "Yes, sir." He placed his hands on his waist and turned to face the rest of them as Coulson headed to his office. "And that gives us all just enough time for a crash course."

"I'm sorry, what?" Hunter asked, leaning his head forward like he hadn't heard what Trip had said.

Trip's smile didn't disappear, and the longer he looked back and forth between Jemma and Hunter, the more apprehensive she became. The answer clicked in Jemma's head a second before Trip gave his answer, and she suddenly wished she could sink into the floor.

"We need to teach you two how to dance."

Hunter laughed out loud. "You're joking, right? We're not going to be dancing."

"You bet your ass you are," Trip said solemnly. "You wanna blend in? You're gonna have to dance." He nodded over to Skye, who was smirking as she pulled up some music on her phone. "Now, this isn't going to require anything fancy. Most of the people there aren't gonna be expert dancers. But you guys are supposed to be married, so you have to look like you've at least touched each other before."

Hunter's mouth was hanging open in shock. "I'll have you know I'm actually quite skilled at dancing, thank you very much. And like you said, these people aren't ballerinas. They're scientists. Probably can't even waltz, for God's sake."

"I beg your pardon," Jemma scoffed. "I know how to waltz. I took the dance elective at the Academy."

"SciTech has one of those?" Trip asked in disbelief.

Jemma hesitated. "Well…it-it was a…trial run, that was…discontinued," she admitted. "But I still made it through the course. Fitz and I both did."

"I was forced," Fitz piped up from behind her.

Jemma whipped her head around. "Oh, don't pretend you didn't like it, Fitz," she replied indignantly before she could stop herself. His eyes widened in surprise, and Jemma suddenly realized how the words might have sounded to him. She wished she could take them back, or at least that he would have held her gaze long enough to figure out what she'd actually meant. But he quickly glanced away, addressing Hunter instead.

"Bit of advice, mate," he said lightly. "She has a nasty habit of trying to lead."

"I…" Jemma began, only to let her voice trail off. "I do not…"

As much as she hated to admit it, though, Fitz was right. She remembered spending so much time in their second year going through the steps over and over again, simply because she always tried to take control. It hadn't even been a conscious decision on her part. She'd just approached the problem of dancing like she would have approached any other problem. But while she and Fitz had learned to work together in the lab and on projects, dancing had been an entirely different endeavor for them. They'd eventually managed to figure it out, after countless hours and quite a few arguments (as well as breaking a few dorm regulations regarding acceptable furniture arrangements). But it'd been a nice change of pace, something fun and different that hadn't revolved around any of their other schoolwork. At least, that's how Jemma had felt. She'd thought Fitz had enjoyed it, too, despite his grumblings. But now she wasn't so sure.

Thankfully Hunter's voice pulled her back to the present. "Look, I'm sure we can handle a couple of dances, yeah?" he asked, looking to her for agreement. "We'll take a few turns, find the target, get the information we need, and then we'll be right out. Easy peasy."

"Right," Jemma said quietly, more to herself than anyone else. "Easy peasy."

Skye gave a disappointed sigh and put away her phone. "Yeah, Trip, as much as it'd be hilarious to watch, I've gotta get Simmons into wardrobe before we take off."

"Hey, works for me," Trip chuckled, grabbing one of the tuxedos off the rack. "Just try not to embarrass yourselves too much out there, all right?"

"Whatever," Hunter muttered, retrieving one for himself and heading off to change.

Jemma stepped forward to approach the dresses, suddenly overwhelmed by the choices in front of her, but Skye grabbed her hand and began pulling her down the cargo ramp. "I changed my mind," she explained as they headed back into the Playground. "None of those are gonna be good enough for you. But trust me, wait 'til you see the one I have in mind."

Jemma followed closely behind Skye. "Where did you happen to find all those anyway?" she asked, gesturing behind her in the general direction of the formalwear.

Skye gave her a curious look. "S.H.I.E.L.D. is a spy organization, Simmons," she laughed. "Apparently when Fury restored this place he kept all the old undercover costumes and added a bunch of modern stuff too. Where else do you think May got that sparkly getup? There's no way in hell she'd ever spend money on that thing."

Jemma was so confused by the words "May" and "sparkly" being used in the same sentence that it took her a while to respond. "Pardon?"

Skye hesitated near a doorway marked with the number 537. "That's right," she murmured, pushing down on the handle. "I forgot you weren't there for that one."

Jemma had about a million questions to ask, but she momentarily forgot all of them as she stepped into the darkened room after Skye. At first, it seemed like just a normal closet. But once Skye turned on the light, Jemma realized that it was much, much more than any old closet. For as far as her eye could see (and she had perfect vision), there were rows upon rows of clothing, but not just any clothing. There was something in every possible style, color, and occasion, as well as period pieces that probably dated back further than S.H.I.E.L.D. itself. Jemma found herself trailing after Skye in awestruck silence, unsure how on earth Skye knew where she was going.

Eventually they paused near one of the final rows, the end of which was adorned with a small plaque that read "S.S.R."

"Skye, I can't wear any of this," Jemma protested. "I'll look completely ridiculous, not to mention out of place. I thought I was supposed to be trying to blend in."

Skye laughed as she headed down the row. "Look, Simmons, what's the point of dressing up if you can't go all out? Coulson already said we probably won't run into HYDRA on the op. So it's just a fancy gala with a bunch of nerds, talking about science. That's totally up your alley. And as annoying as he is, Hunter's not gonna let anything bad happen to you. So just relax, okay? You don't get to be Jemma Simmons for the night, but you still get to be a nerd that loves science. So with God as my witness, you're going to be the best-looking nerd in that whole damn place."

Skye reached into the hangers and pulled out one of the dresses, turning around to face Jemma. "What do you think?" she grinned as she held up the gown.

Jemma's heart began racing again, and she was fairly certain there was a fierce blush on her cheeks. How the hell had she gotten herself into this?

"Oh, my."