A/N: So this is my first Castle story. I hope you like it and I'd love some thoughts as to how I did. I've had the idea for this oneshot since I first saw The Lives of Others promo which was ages ago now, but I hope you'll forgive me for how long it has taken to write this. I'm out of practice. Before I let you read, I'm just going to say I have no experience of hand-to-hand combat or sparring and therefore apologise if it's crap.

Disclaimer: I don't own Castle or any of its characters; I'm just borrowing them for some fun.


Castle was beginning to think that breaking his knee skiing was the worst mistake he'd ever made, and that was saying something, because let's face it; he'd made a lot of mistakes. He'd thought being stuck in the wheelchair all day and not at the precinct was bad enough, but now he was stuck in physiotherapy instead and still not at the precinct. It was his own fault really – he knew that. He just hadn't been able to resist showing off for Kate.

It felt like a lifetime ago that Kate had whipped up a plate of pancakes and a coffee and set them on the kitchen counter for him, kissed him on the back of his shoulder as he eased himself out of bed and dashed out of the loft before she was late for work that morning.

He was going crazy imagining the cases Kate and the boys were getting. Hearing Kate regale her day when she got home from work just wasn't the same. He wanted to be following them in a chase, he wanted to be sitting in on Kate's interrogations, he wanted to be throwing a ridiculous theory on the murderer into the mix just to see that look of exasperation on Kate's face as she turned to stare at him. Heck, he even wanted Ryan and Espo to be teasing him. But instead he was spending his morning completing the leg exercises Dr Forsyth had sent over, bored out of his skull. And he knew that by the time he had gone through the entire circuit of exercises, ran on the treadmill for a half hour and warmed down, he would be too exhausted (and most-likely collapsed on his bed after his shower) to even contemplate catching a cab down to the precinct.

Even more depressed because of those thoughts, Castle huffed a sigh of frustration as he seated himself in the chair of one of the weight machines in his new gym. Kate loved the state of the art gym he'd had installed in the loft so that he wouldn't have to travel for his physio; but he didn't. Still, he soldiered on, using his injured leg to lift the weights. He'd only been doing his physiotherapy for a week, since having his cast taken off, but already he'd progressed from lifting five kilograms to lifting ten kilograms. He was getting used to the burn he got in his under-used muscles, he could feel himself getting stronger but the progress wasn't fast enough for Rick Castle.

After the weight machine, he moved onto doing his step-ups. When the front door opened about three minutes in, Rick thought he was going crazy for a moment. He knew it was still only half ten and that Alexis would be in one of her lectures (and she'd yet to skive a single class) and Mother was running a class at her theatre school. It could only be Kate, but she was meant to be working. They'd had a body drop the day before, a young teacher whose body had been dumped in the Hudson and from what Kate had said that evening, she and the boys were nowhere near closing the case.

"Kate?" he called out but there was no response. He didn't even hear her drop her key into the bowl set on the table by the front door.

He was beginning to think that perhaps boredom had gotten the best of his imagination (again) when he felt her hands slide around his rib cage as she hugged him from behind.

"Hey," he murmured, picking up one of her hands and bringing it to his lips.

Kate smiled in response, pressing a kiss into the space between his shoulder blades.

"What are you doing here? You didn't close the case, did you?"

"It was the boyfriend – Ry and Espo are taking care of the charges, interrogation and all the paperwork," Kate answered.

"That's awful nice of them," he replied, turning in the circle of her arms so they were facing each other, noses touching.

"Mmhm," Kate hummed. "So, how's it going?"

"Like watching paint dry," Castle answered as his hands skimmed down her sides.

"That bad, huh?"

"Bored would be an understatement."

"I can think of a few ways to make things a bit more exciting for y-"

The words were barely out of her mouth before Castle's lips were on hers. Kate hummed, one of her hands sinking into the hair at the nape of his neck, and let her tongue stroke along Castle's lower lip, reciprocating. His groan brought a smirk to her lips and she pulled away, stepping back slightly and letting her hands drop down to the front of his chest.

"As nice as this is, I was thinking more along the lines of joining your physiotherapy."

"Kate," Castle said, his voice coming out as a whine.

"So you don't want to spar then? Huh, Castle?"

He gulped, his Adam's apple bobbing visibly. Kate bit her lip at the sight of it, trying her best to keep from smirking.

"You don't want to…wrestle?"

"God yes!" Castle exclaimed.

"Well then, I guess I'd better take this off," Kate replied, dropping her hands to her own shirt and pulling it from her trousers to unbutton it. Castle stared as, bit by bit, more of his girlfriend's body was revealed. When the shirt was hanging open, Kate flashed her eyes up to his, watching them get darker by the second as she slipped the shirt over her shoulders and let it drop to the floor. "And these…" A muted groan slipped from Castle's lips as she slid out of her trousers, leaving her in just her underwear and walked backwards away from him to the open space in the centre of his new gym.

"Come on, Castle," she said, breaking his entranced reverie. "You can't spar with me from all the way over there."

"So, Detective, are you sure about this?"

"Why? You think you're going to beat me?" Beckett asked, shifting into her stance.

Her voice drew him forwards until he was squaring off against her, both of them standing on the protective mats.

"Oh, I think I can take you," he replied with a leer, his eyes travelling up her body.

Neither of them moved, Beckett waiting for Castle to make the first attack and Castle just too busy staring at Beckett's chest. Rolling her eyes, Beckett reformulated her plan and stepped forwards until she was less than a yard away, easily within attack distance.

If she had wanted to, she could have taken Castle down in one move, sweeping his legs out from under him. She could have kneed him in the side, and then pushed down on his back till he was lying face down on the mats with her sat on top of him. She could have even sent him flying with a high kick but Beckett didn't do any of those things. Instead, she used the fact that Castle was obviously distracted by her body to her advantage, circling around him.

Once she was stood behind him, she struck, sending a reasonably light backhand into his side.

"Ah!" Castle gasped, clutching his side and whirling to face her.

"Focus, Castle," Kate warned, unable to refrain from grinning.

"I'll give you focus," he growled, reaching for her only to have Kate dance backwards from his hands. He shadowed her movements, forcing her towards the edge of one of the mats where there was no escape.

Beckett's heart fluttered in excitement as Castle stepped towards her. His eyes flicked to her left hip, giving her a tell. By the time, he had kicked out with his recently injured leg – the preference for his usually dominant leg instinctive – she had spun away and countered with an elbow jab to his torso. Castle grimaced, but ignored the pain, grabbing Kate's wrist before she could get away again. As she tugged against his hold, he tackled her, his weight pushing her to the floor.

His arms braced either side of her head, holding both her wrists, he declared, "I win."

Beckett raised her eyebrows, the gesture saying 'really?' better than the word itself ever could as she lifted her hips, bringing them into contact with his. Pleasure rolling through him, Castle's grip on her wrists slackened and she rolled them both until she was straddling his legs, leaning over him and, though Castle didn't know how it had happened, holding his wrists against the mat.

"How about a round two? I know I can take you," Castle insisted.

Beckett rolled her eyes again, but stood and helped him up regardless. It was just physiotherapy after all.


A/N: Hope you enjoyed it. Thanks for reading.