Disclaimer: The only part of Castle that I own is the TV on which I watch the show.

The day had to come eventually, and she had pushed it as far as she could. So now she's in the creaky elevator at the Twelfth Precinct, about to get off at her floor, and she's got a case of the jitters. She feels like a rookie. Well, she is a rookie. A pregnancy rookie. Detective Beckett may have been a member of the NYPD for more than a decade, but she's never been pregnant before, especially so visibly pregnant. Today is the first time that she has worn maternity clothes to the precinct and she's bashful about it. When she was leaving for work this morning—fifteen minutes later than she had intended because she had tried and rejected six sets of clothes before settling on this top and skinny jeans—Castle said, "Everyone knows your pregnant, so it won't matter. No one's gonna notice your clothes." Easy for him to say. He isn't the one whose belly now precedes him through the door and he isn't the one who is swathed from shoulder to hip in what feels like an acre of navy blue linen.

She has to fight to keep herself from peeking out of the elevator before stepping into the bullpen. "Suck it up, Beckett," she says to herself, wondering why she had chosen that particular adage, since she sure as hell can't suck up her gut at the moment. Ah, she's in luck. She left home later than planned, but she's still ahead of Ryan and Esposito, who are picking up Frank Matheson, a sleaze who is at the very least a person of interest in the homicide that they're investigating and probably complicit to some degree. She settles in at her desk and is making a good dent in her paperwork when she hears the elevator ping.

"Castle? This is a nice surprise. I thought that you couldn't come in today. Don't you have a meeting?"

"Cancelled!" he sings—actually sings—and puts a cup of tea on her desk. "It'll be so much more fun to watch you grill that slime ball Matheson."

"Mom is grilling a slime ball? Is that like a meat ball? Are you having a barbecue?"

"Your idea of fun is seriously warped sometimes."

"It's one of the things you love most about me, admit it," he says, dropping onto his chair next to her.

"I do. And thanks for the tea."

No sooner has she taken a sip than the elevator pings again, and a trio—a grinning Matheson, squeezed between a disgruntled Ryan and a pissed-off Espo—emerges. "This jerk has been running his mouth since we picked him up on a hundred and thirty-eighth," Esposito says.

"Speaking of which," Ryan says, "he was picking a lock at the time, so we have a few little charges to add. And then we have the pleasure of handing him over to you, Beckett."

"I was picking a lock, but you were picking your nose," Matheson says, beaming at his own high-level word play.

"Shut up," his escorts shout, in unison.

An hour later Ryan delivers Matheson—who is in the middle of a running commentary on the inadequacies of the police department—to the interrogation room. "He's all yours," Kevin says to Beckett, who is already seated at the table with Castle.

"Mister Matheson? I'm Detective Beckett, and this is Mister Castle."

"You can tell him to leave. I'm the only man you need in here."

Beckett ignores him. "Mister Matheson, you've been read your rights."

"Yeah, they shoulda told me I'd be talking to you. I got the right to put on a tighter pair of pants. Show my stuff."

Beckett continues to ignore him. "Can you tell me where you were between one and three a.m. on Tuesday the fourteenth?"

"Well, if I would of known you then, I know exactly where I would of been."

"Mister Matheson—"

"Call me Frankie."

"Tuesday," Beckett says sharply. "Between one and three in the morning."

"I don't recollect," he says, examining his grubby fingernails.

"How about I help you, then."

"Oh, you can help me with plenty, and I wouldn't mind helping myself to a piece of you."

Beckett can ignore Matheson, but she's having a harder time with Castle, who is sitting a foot to her right. He hasn't said a word, but he's radiating enough heat to bake a cake. She opens a folder, takes out an eight-by-eleven photo, and slaps it on the table. "That's you, Mister Matheson, at an ATM on a hundred and twenty-ninth. See the time stamp? It's one forty-three a.m. on the day in question."

He leans forward and looks closely at the photo. "Huh. Not me. Past my bedtime." He pushes the photo towards Beckett and leans back in his chair.

"Well, I guess you stayed up late that night, then. Unless you have an identical twin."

"Only one of me, baby."

"You want to explain to me how you got the card?"

"What card?"

"The one you were using to withdraw eight hundred dollars. Belongs to Joseph Del Vecchio."

"He was a buddy of mine."

"He died thirty minutes before this photo was taken. So, what, he gave you his ATM card and his PIN as a deathbed bequest?"

Silence. The little jerk is actually silent. Beckett stands up, confident that her height will intimidate him.

Matheson startles. "Hey! You're pregnant. I never seen a knocked-up cop before."

"It's a brave new world, Mister Matheson. Get used to it."

"So, who's the lucky guy? Somebody sure got lucky." He's looking her up and down now. "About five, six months ago, looks like. Am I right? Ba-da bing, ba-da boom. Ba-da bang. Definitely bang." He chuckles.

Castle can't let this one go by. He's steaming. "That's enough."

"Whoa! Hey! Wait, it's you? You? One of your little swimmers do the job?"

"Swimming? Who's swimming? Besides me, in here."

Castle is about to lunge across the table when Beckett puts her hand on his shoulder. She takes her phone out of her pocket and calls up her messages. "Hmm. Excuse us, Mister Matheson, we have to step out for a moment." The two of them leave, closing the door behind them.

"What was that?" Castle asks.

"Just a way for me to talk with you for a second. You can't let him get to you. I appreciate your wanting to defend me, but I've heard much worse. Much, much worse. Believe me. I know you're feeling all Daddy Bearish, but you can't get angry. Okay?"

Castle considers for a minute, even though he knows he has no choice. "I don't like it, but okay."

"Okay. Let's go."

"We're back, Mister Matheson."

He looks at Castle. "Can't believe that Slick, there, is man enough for you."

"Really?" Castle asks, calmly. "Not man enough? Why don't you ask your mother?" Beckett squeezes his knee under the table.

"Dad's name is Rick, not Slick. It sounds like Slick, but he's Rick."

"Hey!" He jumps up.

"Sit down," Beckett says, pointing to the recently vacated chair. "Now." He does, glaring at Castle.

"See, yesterday we downloaded some pictures from Mister Del Vecchio's cell phone, which we found inside one of his shoes. The most interesting ones were some selfies of him and a woman, taken not long ago. The kind of photos people used to call compromising." She opens the folder again and turns to Castle. "How would you describe them?"

He looks over her shoulder. "I'd go with kinky. Yeah, definitely kinky."

"And apparently he was going to post them on his Facebook page or Tweet them. He marked them, but they didn't go through. Since he was such a good friend of yours, I'm sure that you can identify her. She might be very helpful in this case, you know." She takes five photos and she lays them out in front of Matheson.

He leans forward again, and immediately rears back. "Son of a bitch! He was going to post those? Of her doing that? No wonder she killed him."

Beckett and Castle look at each other in astonishment. "She killed him?"

"Yeah."

Beckett schools her face and asks matter-of-factly, "Who is she?"

"My ex-girlfriend."

"Aha. And does she have a name?

"Melody Barton."

"And you know for a fact that she killed Joseph Del Vecchio?"

"Sure."

"How do you know?"

"She told me."

"When was that?"

"Right after."

"Right after what?"

"She killed him."

Beckett sighs. "Mister Matheson. Why don't you just tell me the circumstances. Beginning with how and where she told you."

"It was in his apartment. I came over to get something from him and she was there and I saw he was dead on the floor. She was like, 'I shot the bastard.' And I was like 'Oh. Any special reason?' I figured there was, because the guy was scum. He was my friend but he was shagging her when her and I were together. Which makes her scum, too, in my book, which is why I'm telling you. Plus, I'm not taking the rap for this."

Beckett rubs her forehead lightly. "And did she say there was a reason that she shot him?"

"She said he took some pictures and she wanted them back. In case things didn't, you know, work out. He wouldn't give them to her and they had words. She said it was a deal-breaker if she was gonna stay with him and he said it was his right to show her off. And she said, 'What am I, your personal property?' And he said yeah, so long as he was paying for her. So that's why. And for old time's sake I helped her out by looking for his phone but we couldn't find it. So we left."

"And the ATM card?"

"Oh, well, I figured he owed me. Stole my girlfriend. Changed his PIN to her birthday and told me, just to piss me off. So I took the card and got as much money as the ATM let me. I mean, he wasn't going to miss it, right?"

"We'll be back, Mister Matheson." Beckett and Castle rise from their chairs, stunned into silence, and leave the room. And laugh so hard they have to prop themselves up against a wall.

"I love this case, Beckett."

"Me, too. Think he used the same lines on Melody like he did on me?"

"I'd bank on it. I'd bank eight hundred bucks on it."

They finish the case by the end of the day. When they're riding down in the elevator, Castle says, "See? I told ya."

"Told me what?"

"Nobody noticed you were wearing maternity clothes."

She smiles at him. "When you're right, you're right."

At home, they're too tired to do anything but heat up some leftovers, which they eat in the kitchen. He finishes getting ready for bed before she, and when she comes out of the bathroom she finds a present on her pillow. "What's this?" She picks it up and pinches it.

"I thought you might have a tough day at work, so I got you those. Won't need them for a while, though. They're from the baby and me."

"They are? What are they? You didn't tell me, Dad. Shouldn't I know if they're from me?"

"So," she says crawling across the bed. "Do I get to open this now?"

"Absolutely."

She unties the ribbon and unwraps the paper to find a pile of THANKS FOR THE MAMMARIES shirts. There are seven of them, in seven different colors. "Castle!"

"One for each day of the week," he says. "Mother might have mentioned have mentioned them to me."

Beckett topples onto his chest and gives him a loud kiss. "Thanks for the mammaries, Castle."

"I think that's my line, Beckett."

"Isn't it my line, Dad?"

A/N With this chapter, this Summer Hiatus Ficathon story passes the 20,000-word mark! Thank you for being such fantastic readers and reviewers.