For Lou. I hope this is what you had in mind.

Many thanks to Andy for the beta and Chantal for the cover art. It's been a looooong time, but it's so wonderful to be writing for this fandom again :)

Disclaimer: If you recognize it from the show, it's safe to say it isn't mine.

Naked

"This is Detective Kate Beckett, badge number 0334. I've been exposed to high levels of radiation. We need emergency services right away."

After Beckett hung up the phone, everything happened fast. EMS arrived. The police. The fire department. A hazmat team. People were rushing around, and in the chaos Castle got separated from Beckett. He was spinning around, searching for her in the crowd when he suddenly felt himself being roughly grabbed by the shoulders.

"Right this way," a man instructed, forcing Castle into step with him and another man; both were dressed in suits that were part Michelin Man, part astronaut.

Castle protested, fought back, inquired multiple times as to the location of his partner, but to no avail. The men remained completely unaffected by his outbursts.

"Just…tell me how serious it is," he shouted finally as they dragged him down the hallway, already forcibly removing his jacket.

"Take off your clothes," one of the men demanded.

"What?"

"Take them off. All of 'em."

"Okay, I don't know who you think you are, but this isn't funny anymore," Castle snapped.

"It's not meant to be," the man stated flatly as they shoved him into a small, enclosed room, tossed his jacket in after him. "Now take everything off, put it in this bag, and follow the posted instructions."

The door shut behind him and they were gone, leaving Castle standing alone and confused in a tiny room with a bag for his clothing, a small shower stall, and instructions for proper decontamination protocols.

What the hell had they gotten themselves into?

After fumbling through a shower, Castle stepped out from beneath the spray and exited - still dripping wet - through the opposite door as instructed. The door opened into another tiny room made of the same white materials that surrounded the hallway they'd drug him down and the shower room he'd just exited.

He rapidly surveyed his surroundings, eyes blinking to adjust to the dim light. There wasn't much to see. A single bench. No windows. One other door.

And standing just a few steps away at the opposite side of the small enclosure, with the same terrified look in her eyes as he was sure was in his own, was Kate Beckett.

Naked and dripping wet.

"Beckett," he stammered in surprise.

Their eyes met and locked, staring at one another with a mixture of utter shock, terror, and no small amount of attraction; Castle couldn't stop his body's reaction to her, couldn't do a damn thing to hide it.

After a long moment Castle's gaze flickered downward, and at the movement of his eyes Kate suddenly seemed to remember that she was completely naked, water from the shower still dripping from her hair, running in rivulets down her body.

"Castle," she hissed, but the menace in her voice was drowned out by something that sounded suspiciously like arousal. "Stop…staring."

He obediently lifted his eyes back to hers, but that was almost worse because she could see everything shining in their depths. Attraction. Arousal. Desire. Lust. But there was something more. Something that she really didn't want to put a name to.

"You're gorgeous, Kate," he murmured, taking a step towards her.

"Castle," she warned, but it was breathy and completely devoid of conviction. Her head was spinning, her palms were sweaty, her heart was pounding its way out of her chest, and she was rapidly losing the ability to resist him. Not that she wanted to. He was a big man, strong and sturdy, and she knew he could engulf her, surround her, make her forget everything else.

He took a second step, a third, and then a fourth, until he was right in front of her.

She should really back away. He was too close and he was gazing at her with far too much emotion and she had a boyfriend...

Castle extended one arm, hand rising to tenderly cup her jaw.

She didn't stop him. Couldn't find it in herself to move away.

He gently thumbed away a droplet of water, the brush of his thumb tender against the soft skin of her cheek. "Absolutely stunning," he whispered, voice deep and husky.

"Rick," she choked out. It was all she could manage. She couldn't breathe, couldn't think, and it had nothing to do with the adrenaline of being exposed to radiation.

No, right now she was exposed in an entirely different way.

Kate's eyes snapped open – when exactly had she closed them? – at the loss of Castle's touch, and she lifted her lids to find him taking a step back, hand falling to his side.

"Wha…" she began, had to clear her throat and force her voice to work. "What are you doing?"

"Just speaking the truth," he murmured.

She blinked and looked away. She couldn't deal with the intensity of his gaze right now, the desire in his voice, or the candor of his words. She knew he had feelings for her. Strong feelings. And ever since that night in the alley a month and a half ago, she'd been finding it harder and harder to deny that his feelings were very much reciprocated.

When she didn't reply, Castle wisely fell silent, busied himself with looking around the room once again. He stepped up to the wall, unzipped a corner of one of the panels to reveal a layer of clear plastic. The world outside was blurry through the thickness of the material but he could see the radiation teams hustling around, still clad in their giant orange suits.

He watched for a few minutes, observing as much as he could. Ordinarily, he'd find this a fascinating opportunity for research, but given the circumstances, he couldn't manage the smallest inkling of excitement. A third hazmat team arrived and Castle's heart sank.

This wasn't looking good.

After a prolonged silence, Castle finally spoke.

"Those hazmat teams are only staying in the building for about a minute at a time."

"Maybe it's just standard protocol," she answered, clinging to the only shred of optimism she could find.

Castle re-zipped the window, turned to find Kate leaning back against the edge of the tent, sliding down the wall until she was seated on the floor. She drew her knees up in front of her chest, wrapped her arms around them. A shield against the air, the world, Castle's loving gaze.

"Or maybe it's just too hot in there to handle." He mimicked her actions, sliding down the wall next to her so they were seated side by side. "That radiation detector of yours. Does it have a scale on it? You know, like chest x-ray to Chernobyl?"

Kate didn't meet his eyes, and he could hear the terrified tremor in her voice as she spoke. "Maxed out."

Castle pulled his knees more tightly to his chest. "Oh."

"Yeah," she breathed.

She swallowed heavily and Castle swore he could see a trace of moisture accumulating in the corner of her eye. He reached out, right hand coming to rest on her left knee, the contact comforting to himself and, he hoped, to her.

His palm settled over the hard bone, thumb tracing a gentle line across the outside of the joint, and a shiver rippled through her at the softness of his touch.

"Cold?" Castle murmured.

"No," she answered, the word slipping out before her brain could catch up. She jerked her head up, looked away. "I mean…"

"Kate," he called softly, allowing his hand to fall back to his side.

"I'm fine," she insisted sharply.

"We're stuck in a decontamination tent without our clothes and we have no idea what we've been exposed to," Castle stated matter-of-factly. "Neither one of us is 'fine' right now."

She huffed a sigh, refused to meet his eyes. "Can we talk about something else?"

"Sure." He paused, hesitated before broaching the subject. "How's Josh."

Kate's jaw tightened, and he almost thought he saw her roll her eyes. "Fine." When Castle didn't speak, she elaborated. "He's um…he's on his way to Haiti to do another Doctors Without Borders mission."

"How long?"

Kate shrugged. "I dunno. Don't really care, either. It was never gonna work."

"You and Josh?"

She shook her head. "I think I've known for a while that it wasn't what I wanted. But I didn't realize what that was until…" she trailed off.

"Until…?" Castle prompted.

She tightened her arms around her knees, as though it was the only thing holding her together. Maybe it was. Between the fear, the uncertainty, and being this close to Castle while completely naked...

She'd already shared far too much.

Kate shook her head. "Never mind."

"Beckett," he coaxed.

She dropped her head back against the wall of the tent and closed her eyes, inhaled deeply and released the breath in a long, slow exhale. When she finally turned and met his eyes, Castle could see the steely resolve in her gaze.

"Until today," she confessed softly. "The way you were looking at me…like you were in awe…" Kate sighed sadly, shook her head, and he could hear the pain and shame in her whispered admission. "Josh and I have been together almost nine months and he's never looked at me like that."

Castle's reply was automatic, the words tumbling out almost in anger at the thought that any man could underappreciate Kate Beckett. "Well then he doesn't understand how damn lucky he is."

She shrugged, eyes fixed firmly on her knees once again.

"Kate."

Her gaze didn't lift. "What?"

"I mean it," he reiterated. "You're intelligent, you're beautiful, you're compassionate, and you're the strongest person I've ever met. What man wouldn't be in awe of you?"

She finally tilted her chin, lifted her eyes to find Castle watching her intently. His eyes were dark and serious but clear, and she could see in them the depth of his feelings for her.

Her stomach fluttered and she could feel the pounding of her heart accelerate. This wasn't some attempt to lighten the mood, to make her forget about their current predicament.

This was Castle pouring his heart out. It was written all over his face.

Kate blinked, made a split-second decision, and before she could talk herself out of it she leaned in, closing the distance between them, and pressed her lips to his.

Castle froze, and she both felt and heard his sharp intake of breath. He didn't respond right away, and she was about to pull away in embarrassment when one hand rose to cup her jaw and his lips finally moved beneath hers.

But as she was gaining confidence, he seemed to be losing it, and she felt him pull away, their lips separating with a pop that echoed through the silence.

Castle rested his forehead against hers, allowing their warm, rapid breaths to mingle in the small space between them. His hand settled on her shoulder, thumb gently tracing the angle of her collarbone.

"Kate," he breathed, voice hoarse. "We can't."

"I thought you wanted this," she whispered, leaning back to meet his eyes. "Me."

"You saw exactly how much I want you," Castle uttered in a low voice, and she could hear the insecurity in his words, was reminded of just how thoroughly exposed he'd been half an hour ago. Kate was silently thankful that her desire was much easier to hide. "But not like this. You're scared and upset and you have a boyfriend."

"For now," she muttered in frustration.

"For now," he echoed softly. "But after this case, after you…"

She nodded in understanding. "Yeah."

"You know where to find me."

The sound of a zipper shattered the silence. Castle hastily dropped his hand from her shoulder and two sets of eyes lifted in unison to find a radiation suit-wearing man entering the tent.

Great.

The only thing that could possibly make the uncomfortableness of their current situation even worse.

They weren't going to die. That was the good news. The bad news was that there had in fact been a bomb in that storage unit. A bomb that was now missing.

It was time to get back to work.

"Can you, uh, not look?" Kate asked as soon as the man left.

"What?"

She indicated the bags of their clothing and personal items that the man had deposited by the door. "While I get dressed."

"Oh, sure, right." Castle wrapped his arms around his knees, dropped his forehead onto his forearms. "Go ahead."

Kate crossed the tent, risking a glance over her shoulder as she did so, but Castle's gaze was still dutifully averted. She grabbed the bags, tossed his towards him as she strode to the far corner of the tiny room to change.

He lifted his head tentatively, snatched the bag and made his way to the opposite edge of the tent.

"Can I turn around?" Castle asked, breaking the silence after a couple minutes.

"What?"

"Are you dressed?"

"Oh, uh, yeah," Kate answered.

He turned to find her combing her fingers through her still damp hair, scrunching up her face in discomfort as they caught in a knot. She finished detangling her hair and secured it into a braid while Castle took a seat on the bench to put on his socks and shoes. Kate slipped into her jacket, lingering by the door to wait for him as she worked the zipper.

Castle joined her after a minute and she turned to unzip the door, paused and turned back to him.

"I'm sorry," she voiced softly.

Castle shook his head. "Don't be."

"I just wish…" she trailed off with a shake of her head. She didn't know what she'd been planning to say, anyway.

"Hey." Castle reached out, caught her hands in his own. Her eyes dropped to their joined hands, slowly rose to meet his heartfelt gaze. "I've been waiting for two and a half years," he reminded her with a gentle smile. "I can wait a few more days. If we're gonna do this, we're gonna do it right."

She closed her eyes, nodded, more to herself than to him. He was right. Whatever this thing was between them, they owed it to themselves to give it a shot. And the only way to ensure that they had a fighting chance was to start with a clean slate.

Kate took a breath, exhaled slowly, and when she met his eyes again, Castle could see that her defenses were back in place, her jaw set with determination.

"Come on," she murmured with a gentle smile.

Castle's eyes lit up, excitement painting a smile across his face, and Kate shook her head but her own smile didn't fade. God, she adored this man.

"First things first. We have a murder to solve."

END

Prompt: when they're put in that decontamination tent in Setup, their clothes have been removed