This started as an entry for the fanfiction-Subreddit's February Challenge: Clueless Detective. It's not February anymore, but I had this little tidbit sitting on my drive ever since and couldn't stop smirking whenever I saw it, so here it is. You're welcome.

New York City, 12th Precinct

Homicide detective Kate Beckett leaned back into her chair with a heavy sigh and started massaging her temples. It wasn't even noon, and their new case had gone sour already.

When the elevator chimed in a new arrival, she forced one eye open, and hoped her fellow detectives, Esposito and Ryan, were back with some good news from the interviews. Instead, she was greeted with the sight of Rick Castle, her writer tag-along of about two years (and author of her favorite novels, not that she would ever admit that to him).

This distraction wasn't exactly unwelcome, but the grim look on his face didn't bode well. Swallowing the sigh that she had had on her tongue, she forced a smile on her lips.

She knew that she didn't have to make an effort. It wouldn't take long for him to see through her half-hearted facade, and as soon as he realized that her smile was fake, he would take the hint. For all his faults and annoying habits, this nine year old on a sugar rush was surprisingly good at reading people.

"Beckett!" he said in greeting, equally honest smile slipping into place as he neared her desk and plopped down on 'his' chair by her desk.

"Castle," Kate replied as she closed the manila folder in front of her and leaned back in her chair, "what brings you here?"

He squirmed and fidgeted around before answering. She had been wary of his intentions already, now she was downright suspicious. She had interrogated suspects in cut-and-dry cases who had kept their cool better than Richard Castle right now.

"Kate, I normally don't do this, but… I need to ask a favor." The young detective frowned in worry at the sight of her partner. There was little left of the self-described ruggedly handsome man in front of her, with dark, sunken eyes telling stories of sleep deprivation.

"Castle, what's wrong?"

"It's Alexis. She…"

Hearing his daughter's name put her in full alert mode. As it seemed that all the maturity that Rick Castle was lacking had been donated to his daughter, she genuinely liked the young woman, and she would hate to walk in the poor sod's shoes who tried to harm Alexis when she found the perp.

"I can't believe how blind I've been… but I think Alexis has a boyfriend." After this revelation, he leaned back into his seat and stared at her expectantly.

Katherine Houghton Beckett, youngest female detective in the history of the NYPD and hardened interrogator, froze. A thousand thoughts raced through her mind, some of whom contemplated bursting out in laughter like a crazy person, while some others started mentally filling out the paperwork required after strangulating a civilian in the bullpen - just to be prepared, should the need arise.

Beckett's voice was reduced to a low growl when she found words again. "What?!" she pressed out; she had heard him just fine, but she wanted to make sure that flying off the handle was warranted. She reserved those outbursts for when the situation really called for it.

Scaring her into thinking that something had happened to Alexis felt like one of those rare occasions.

What was that form again? The part of her brain that was busy with paperwork was drawing a blank on the final form to fill out for strangulation of civilians.

"I know, right? I was shocked as well when I found out," Castle said, the meaning behind her word completely flying over his head. "I thought she knew that she could come to me with stuff like this."

"Well, it's Alexis," Beckett supplied, barely keeping it together; "whatever her reason, I know it's a good one. Besides, she's old enough to make her own decisions. Probably better ones than you made, back when you were her age, or now."

"Maybe you're right," he muttered, oblivious to the fact that he was only still sitting in this chair of his right now because Beckett didn't want the paperwork. "It's just… it hurts that I learned of it like this, you know? Right here," he added and clutched his chest where his heart was.

"And you're absolutely certain about this?" Beckett asked and crossed her arms. She couldn't explain it herself why she was even going along with this.

"Oh, one hundred percent," he assured her with that wide-eyed look of his that she had dubbed the 'Trust me, I think I know what I'm doing' look. "She comes home at random times in the evening. When I ask her about where she had been, she just says 'studying with Jonny'. Which would be nothing special, except for two nights ago, when she went there without her study materials." He grinned at her triumphantly, as if he had just broken the case wide open for her. "Not to mention she seems exceptionally happy these days and she even wears makeup, albeit in subtle doses. She never does that!"

"And you think she's not just studying with him?" she asked.

He waved her concerns away. "Pff, as if. She's not studying with him at all. She is extra careful though, and always takes a cab from his place, I called the company... Maybe I could ask Jonny if he knows more."

Suddenly, it clicked, and all the anger and annoyance dissipated as she realized that Castle hadn't made the connection yet. Oh, this should be good, she thought and caught the smirk before it could make its way onto her face.

She leaned forward as a plan began to take form in her mind. "So, let me get this straight: You want my help finding out about Alexis' mysterious new boyfriend?"

Castle sagged down into his seat, relief clearly visible on his face. "Yes, thank you."

Kate allowed a small smile to come forth. "You know what, your idea wasn't half bad. Let's get Jonny here."