Per request of Mikayla… Happy Birthday, dear! Prompt from tumblr's castlefanficprompts: "We both live at the beach and it's spring break so we bond over the hatred of college kids ruining everything." Set circa mid to late season 5.

He wasn't necessarily trying to fall asleep, but the constant squealing coming from the beach below was disruptive enough to pull Castle out of his scotch-induced haze. He moved away from the blank computer screen and peered out the of the sliding glass doors of his office, hesitant, as if one of the twenty-somethings below would actually bother looking up.

Once he was sure that he would go unnoticed, Castle slid the door open and slipped out into the darkness, eyes trained on the bonfire below.

Balconies had been one of the most important features in his Hamptons home, and they still were in a way, but originally it had been for the always curious Alexis. He'd stand her tiny legs up on the railing and hold her tight to him, reveling in her joyful babble before she'd tuck herself into his chest and ask him to tell her a story.

The smoke from the fire had gotten in his eyes, so Castle shifted away them, but paused when he saw a small light from the house to his left.

He knew that someone had moved into the modest cottage beside him, even saw the movers-or two men who shifted boxes like brothers-but had yet to even learn the name of his new neighbor.

He watched as a woman stepped off of her deck, flashlight in hand, and only began to react once he saw her veer towards his back door, instead of the beach below.

Castle stumbled a bit, whether because of scotch or surprise he did not know, and made it onto the first floor just as he heard a nock.

He was a bit breathless when he swung the door open, but was met with the face of a very beautiful, very surprised woman. "Oh, hi."

Castle cleared his throat, eyeing the loose bun that her hair was pulled up in, a few strands falling down past the slash of her cheekbones and hitting the tops of her shoulders. She sported a red sundress, perfect for the daytime, but obviously a bit too light for the night. "Hi."

"I'm Beck… Kate. I just moved in last week. I should've introduced myself sooner."

Castle opened his door wider and motioned for her to come in. Kate barely hesitated, before smiling and stepping inside, slipping out of her sand-coated flip flops. "No, it's on me. I should've offered to help you move in. I've been a bit distracted, I guess." Kate smiled again, and Castle felt something warm settle in his chest. He began to walk towards his kitchen, and she followed, peering around at the impeccably decorated mansion. "I'm Rick, by the way. Rick-"

"-Castle," Kate cut in, before blushing. "I recognize you from the picture on your book jacket." And from a book signing.

"I see I have a fan."

Kate shrugged, but he could see the playfulness in her hazel eyes. "Killing Derrick certainly crushed me, but I read your short-lived Finite Laughter."

Castle cringed and took down two glasses, but paused at his booze cabinet. "Would you like anything to drink?"

"Just water is fine." Castle poured two glasses from his sink, sighing at the much needed slide of cool, non-alcoholic liquid down his throat.

"And short-lived? That was one of the longest single pieces I've written."

Kate smirked. "A bit too much of an homage to David Foster Wallace's Infinite Jest, if I do say so myself."

Castle grinned, and oh-there was that warm feeling again. "You do a lot of reading?"

Kate pulled her glass to her lips and Castle watched in slight awe as she ran her tongue along the edge, before setting the glass back down on the countertop. "That's what I was trying to do, before the kids outside got too loud. That's actually why I came over here…"

"Hmm?"

"Well, I'm new around here, so what's the protocol for things like this?"

Castle shrugged. "Just local college kids on Spring Break. We usually let stuff like this go."

She quirked an eyebrow, before sighing and going for another sip of water. "Sorry, I'm a cop. It's just my instinct to ask."

Castle's eyes widened, the cogs in his brain already turning as he thought of question after question to ask her. "Not a Hamptons cop I take it."

She blushed and bit into the plump flesh of her bottom lip, thoroughly distracting Castle. "Uh, no… a detective in Manhattan. Well, a lieutenant now."

"Oh, wow." Castle grinned and walked around the countertop so that he could sit next to the newfound mystery of a woman. "Up for captainship anytime soon?"

Kate shrugged, but he didn't miss the way her eyes lit up. "Maybe in a few years."

They both cringed at the sound of playful shrieking, which had Castle back up and moving, reaching towards the wine fridge. "Would you like an actual drink? It'll probably be a long night. No pressure, though."

Kate tucked a few loose strands of hair behind her ear and bit into her lip again. "I don't mean to intrude."

"You're not bothering me… I wasn't getting much work done anyway."

Kate stood up and walked around the counter. "Okay then. Wine would be great." Castle realized for the first time the substantial height difference between them. "You're writing again?"

"Trying to."

She cracked a smile as he selected a bottle, uncorked, and decanted it before pouring them each a glass and walking with her towards his living room. "This is a gorgeous house."

He took a seat on the tan couch, facing her as she spoke. "Thanks. The size seemed like a good idea a few years ago, but now that Alexis, my daughter, is off at college… I don't know, it just seems empty now."

As if on cue, the kids outside started singing a drunken rendition of Happy Birthday. "She could be one of them."

Castle groaned. "Don't remind me."

"I remember my first spring break. It was actually my senior year of high school." Kate laughed, a head-back, carefree kind of thing, and Castle couldn't help but smile in turn. "We spent it in Florida… Panama City Beach."

"Oh, wow."

Kate grinned. "It was a lot of fun, from what I remember anyway."

"What about in college? Where did you go?"

Castle wasn't quite sure what he was expecting when he asked, but it wasn't for Kate's face to fall, or for her to down half of her wine. "I didn't."

"Oh?"

"My mom died my freshman year, and… I kind of stopped caring about stuff like that." Kate sighed and shifted her gaze to the people outside, dancing around the fire and shouting different expletives.

"That was probably for the best," whispered Castle, trying to lighten the mood.

Kate shrugged, tracing her long, slender fingers along the edge of the wine glass. "I don't know. It's moments like those that I think I miss the most sometimes… even though they didn't even happen." She took another sip of wine before setting the glass down on the coffee table and leaning back. "Sorry, I know that sounds stupid."

"Hey, no. That makes sense." Castle reached for her hand and gave it a gentle squeeze. "Not stupid… human."

Kate blushed under his gaze, but didn't pull away. "Thank you."

Just then Castle stood up. "Don't thank me yet."

Kate's hand was still clasped in his, and she stood up as to not break the contact. "What?"

"I have an idea."

She allowed him to lead her through the house and outside onto the beach below, both barefoot so that their feet sunk into the sand. "I'm intrigued and nervous."

Castle grinned at her as they passed the college students and made their way towards the practically black water. "Don't be nervous. We're going to have Spring Break… just for tonight."

"What?" She let out a giggle as the cool ocean water hit her toes.

"Trust me on this one."

Kate sighed, a happy, content thing, and held his hand as they waded further into the water. "Okay."

While Spring Break eventually ended, their time together never did.