"Three adults for swimming, please," Beckett said to the pretty young girl behind the desk, handing over a twenty-dollar bill.

"Here's your change, enjoy your evening," the girl said, handing Beckett the best part of five dollars.

They walked over to the communal changing area and slipped off their shoes, then each of them, Castle, Beckett and Alexis, found a cubicle to change. Beckett and Alexis put all their things in the same locker and decided Castle could have his own, given that they were ready and getting cold and he was still yet to be found.

When they did find him, it turned out he'd already acquired his own locker and was in fact fixing his hair in the mirror behind a large row of lockers.

"Crap, it's freezing!" Alexis complained with a giggle as she let the water lap her feet over the ladder.

"Damn," Beckett said with a look of agreement as she dipped her foot in the water. She sighed and jumped right in to her waist. "Ooh, it's cold!" she laughed and ducked under surface.

Alexis eased her way down the ladder while Beckett floated on her back and Castle watched them from a few feet back from the edge.

"Come on in, Castle, the water's fine!" Beckett called with a laugh as Alexis sent a little splash flying her way, which she returned before a red head poking above the surface was all that could be seen of her at intervals as she swam the length of the pool. It didn't take her very long; the whole thing was only twenty metres long and the deep end went down one-hundred-eighty centimetres, so it was little more than a training pool, really.

Castle at last eased into the water alongside Beckett and stood waist-deep in it. Then he didn't move.

"What's up, afraid you'll mess up your hair?" Beckett laughed.

"Can I admit something, Kate?" Castle said shakily.

"Of course, what is it?" Beckett asked, the joking gone from her voice.

"I can't, strictly... swim."

There was a beat of silence.

"Oh," Beckett said with a smile. "Well don't worry, you'll pick it up," she told him with a wink, and took off in freestyle for the 'deep' end. She returned not even a minute later, smiling. "C'Mon, Castle, I'll teach you," she said. She had a fond look in her eye, the kind that said 'I love him despite these faults.' That said her love for this man was unconditional.

"OK, elbow out first," Beckett demonstrated, leaning forward in the water. "Castle?"

"Mm?" He answered as if broken out of some reverie.

"You'll need to get... wetter... than that," Beckett replied, looking at him just standing there. After a moment of his just looking at her blankly, she adopted her 'really?' facial expression and stood. From there, she proceeded to throw so much water at Castle he shouted, "Woah!" and fell back into the pool.

"Right, now we can get started."

Castle watched her intently. "OK, go," he said.

"Elbow out," she demonstrated, "Arm over, stick your hand in and as you pull back, move it from side to side like this."

Castle tried to repeat this.

Castle made a complete mess of it.

Beckett laughed.

"Hey! Don't laugh!"

"I'm sorry, you're just so cute!" Beckett said and pinched Castle's cheek. "Let's try again."

The exercise was repeated for quite some time while Alexis flew back and forth and Beckett floated on her back between demonstrations that were fast becoming old. "OK, stop," Beckett said, and told Castle to hold onto the edge. "Now kick," she said.

Well that was a mistake, she quickly thought as spray flew halfway across the pool. "Stop!" she cried. Move your legs more like you're walking, forward and back, not like you're riding a bike, up and down, OK?" Castle attempted this and wasn't so bad. Emphasis on so.

"Why don't you work on that for a while?" Beckett said quickly as Alexis went past, and fell into stroke beside her.

Together, Beckett and Alexis swam the length of the pool for a considerable amount of time, covering, say, five-hundred metres, happy in each other's company, perfectly in time with one another and not feeling the need to fill the silence. They started to slow; Alexis, especially, had been going longer than Beckett. Soon they just slipped into breaststroke, during which there was something of a water fight. After so much water went flying around, a lifeguard eventually came to the edge to ask the pair to stop. They fell about laughing, then turned their attention to Castle. Alexis took off again, though not so fast this time, and Beckett returned to his side.

He didn't see her approach, so she surprised him when she emerged suddenly from the water and kissed him on the lips. "C'Mon," she whispered close to him, then smiled, grabbed his wrist, and yanked him into the water alongside her, headed for the deep end. Castle cried out in surprise.

"Wait, I can't– you know– gah!" Castle tried to speak. Beckett's answer was simply to drag him all the way to the end. She guessed that he could probably touch the bottom, but it was enough to pull him out of his comfort zone. She pulled him out, away from all the edges, into open water.

"Now swim," she instructed, backing slowly away and letting go of his wrist.

At first he flailed with a panic-stricken look upon his face, but he started to tread water, very messily, but somehow effectively.

"Swim," Beckett repeated.

Shoulda been a LOT more specific Beckett though as Castle cautiously doggy-paddled toward her.

"Not quite like that," she said with a smile and pulled him up. They were up to their necks standing about two feet apart, Beckett closer to the shallow end. "OK, remember Demming?" she asked him.

Castle's face immediately dropped as though he were glaring at a person who wasn't there; the ghost of the robbery cop still irritated him, though Castle had long since beat him of his prize: Beckett herself.

"He's standing behind you," Beckett told him, then quickly added, "Imagine," when Castle actually turned to look.

"Oh, OK."

"Flat on your stomach," she instructed, "Elbow him in the face, break his nose."

Castle's arm produced itself from the water as it should in the freestyle stroke. "OK..." Beckett hadn't really thought this far ahead. "Um, he's fallen back, so... Reach out to grab my hand!" she told him, offering her palm. As Castle arced his hand over to reach for hers, she snatched it back so his fingers sliced into the water's surface. "Pull your hand back through the water, palm facing the back of the room," she ordered. Castle did so. "That was a swim stroke!" she congratulated, silently adding 'almost.'

He slowly repeated these stokes so he could quickly walk towards her as she backed away.

"Now your feet," she said. "Remember to move them like you're walking, not cycling."

Castle did so and made slow progress along the pool's length, occasionally faltering and tipping one side, or straightening his arm instead of sticking out his elbow, maybe kicking to high so his foot appeared.

When Beckett looked at the large frosted glass clock on the wall, she was surprised to find it had been a whole half hour since she parted with Alexis, and well over an hour since they'd initially arrived. "You ready Castle? It's quarter-after-nine," she told him as she gazed out at the night sky. Already summer was fading, she observed; it was pitch-black already, the dark stillness interrupted only by the distant orange glow of light pollution and the occasional pair of headlights.

Reengaging her focus on the pool, Beckett could not see Castle anywhere. She turned all the way around and glanced at every face, found Alexis, but could not see him.

Beckett cried out as hands grabbed her ankles. She flew backwards, tumbling into the water. She barely had the time to take a gasping breath. Underwater, Castle's lips found hers and the kissed for a precious moment, before bursting up above the surface. Though being under the water took away some sensation, there was still a charge between them that was easily forgotten when she was dealing with his childlike innocence or his writer's block, or he with her easy frustration or her insistent need to prove herself.

Castle smiled down at Beckett and analyzed the curve of her mouth, the sharpness of her eyes, the honey-like brown her eyes had become today; he wondered if they'd be greener again tomorrow. Her wet hair was silky and straight, some of it hanging over her perfectly arched eyebrows. Sometimes, Castle thought, she just seemed too beautiful to be real, too perfect to be human. Too amazing to be his.

But she was, and he reached out for her, leaned in to kiss her.

"No petting!" Alexis told them, popping up, seemingly, from out of nowhere.

Beckett smiled, while Castle shot her his 'Why?!' look, though he couldn't keep it up for long before laughing and taking her hand. "Come on, I'm cold," he said.

While Alexis and Beckett showered alongside one another, Alexis's black bikini in stark contrast to her white skin, Beckett's tan one-piece with the slits in the sides revealing only a mildly more golden shade, Beckett could not prevent from smiling.

The showers had so much pressure the streams of water felt like nails, though their shared shampoo made their hair super-soft. Alexis watched Beckett smile and thought back to her last few years of high school, when Beckett had only appeared when rugged over her mother's case, or frustrated she was missing a link. She'd thought it strange, at first, two partners becoming lovers, but she surmised that it had been clear to her for a long time that they were 'destined' to be together, as some might say. It was so clear each made the other happy, just look at Beckett beaming now! And how she'd worked with him – Alexis often ran out of patience, she wasn't sure she could have stuck to all those demonstrations. She forgot these things came easily to her, that her father struggled at times. But then, should she try to right a book, it was most likely reach the New York Times' worst book list. She smiled as she thought about her father, looking at Beckett.

"You ready?" Beckett asked softly, looking down at her.

"Mm-hmm, Alexis answered, and nodded.

They walked over to their locker and Beckett pulled the key from her ankle. They had just removed their things and placed them in adjoining cubicles when Castle felt it appropriate to throw a bucket of water over the tops of the stalls.

Simultaneously, the girls opened their doors. And glared.

When they walked home, Beckett and Alexis were a little damp; Castle had gotten their clothes wet. But Castle was desperately scanning the streets, making sure no-one was watching, as he walked around drenched in pink shampoo and conditioner. It had seeped into his clothes; he looked like a four-year-old with a recent yoghurt-related mishap.

Beckett and Alexis looked at each other and grinned. They quietly high-fived each other behind Castle's back. Then, to soften the blow a little, Beckett stood on her tip-toes and kissed Castle deeply. Alexis walked on ahead, rolling her eyes but smiling.

The kiss was long and slow; Alexis was halfway up the street when Beckett at last pulled back.

"Pink is really your colour," she whispered, and ran after Alexis.

Castle stood for a moment, smiling. He turned, and walked after them.