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

Castle is sitting at his desk, trying to write, or pretending to write. They had gotten home so late last night after that monster of a case, and he's exhausted. But now it's over: Beckett is at the precinct, scaling an Everest of paperwork, and he's at home, scaling nothing. He's thinking Nikki-and-Rook thoughts, or he should be, but his mind keeps wandering to Beckett-and-Baby land. Who knew that a pregnant Beckett would be so adorable? Even more, who knew that a pregnant-by-surprise Beckett would be so sunny? But she is.

Okay, Rick: think Nikki, think Rook. Hmm. Maybe he should lie down. He gets some of his best ideas when he's horizontal. "It's the truth," he insists to the empty room as he takes to his office sofa in supine search for inspiration. He's asleep by the time "truth" leaves his barely parted lips.

Two hours later he opens his eyes, wide, to see Beckett standing right next to him. "You're home," he says. He hadn't even heard her. What kind of a father is he going to be this time around if he doesn't even notice when someone comes through the front door? Beckett could have been a marauding something, a marauding something or other, and he'd have slept right through her plundering the loft.

"Plundering, Castle?" she asks.

"What?"

"You said 'plundering'."

"I did? Oh, right, just dreaming."

"Hell of a dream there, Sir Richard. Plundering, eh? Where did you stash your armor?"

"It's around here somewhere," he says, sitting up and looking blearily around the room. "Or maybe it's at the dry cleaners."

She sits down beside him and gives him a kiss. "Rough day at the office, huh? You were really sound asleep. I'm sorry I woke you."

"How can you look so perky, Beckett?" He stops for an enormous yawn. "You slept even less than I did last night."

"I dunno. I think getting this energized me," she says, handing him a small, dark green shopping bag.

"Ooh, a present? You know how much I love presents! What's the occasion?"

"C'mon, Dad, just open it!"

"None, really," she says, with a smile that suggests an untold story.

He's onto her. He knows there's something. "And?" he asks, rotating his hand in the universal gesture for "keep talking."

She rests her head on his shoulder. "This morning, while you were still more or less unconscious, I was making tea in the kitchen and looking at the sonogram printout on the freezer door. And I thought to myself that our baby's first picture deserves a better setting than that. We shouldn't see it just when we're getting frozen spinach or an ice cube. So I got this on my way back from work." She gives him a little nudge and points at the bag. "Go on."

He tries to behave like an adult when he's unwrapping something, but he hasn't mastered it. He lifts out the present, tears the paper from the box, and yanks the top off to discover a nest of soft green tissue paper swaddling an exquisite, simple silver frame. "It's the baby!" he says, running his index finger over the sonogram image inside. "Thank you."

"Yeah, Dad, it's me! Mom told the lady in the store all about me. She never talks to anyone about me, except to you. And the lady said, 'A gorgeous baby deserves a gorgeous frame.' That's nice, right?"

Beckett moves her head so that her chin is on Castle's shoulder, and she looks down at the frame. "Baby's a thumb sucker."

"What's wrong with that?"

"A gorgeous thumb sucker," Castle says, turning his head to look at her, just inches away. "Did you suck your thumb, Beckett?"

"Put it this way. If the kid takes after me, you'll be glad you're rich. My parents practically had to take out a second mortgage to pay for my braces because I sucked my thumb for such a long time. What about you?"

"Nope."

"Really, Dad? How come?"

"Are you kidding? You, Mister Orally Fixated? You never sucked your thumb?"

"Really. Ask my mother."

"Right, Mom, ask Gram. I bet he did. He likes fun things, and sucking your thumb is definitely fun. I bet he's telling a big fat fib."

"You're on, buster," Beckett says and slides her phone out of her pocket. "I'm going to call her right now."

Moments later, Martha answers. "Hi, Darling. I'm about to have a drink with an old friend. Is everything all right?"

"We're all fine, Martha." She glances sideways at Castle. "I've got you on speaker, and I wanted to ask you something. Did Rick ever suck his thumb? When he was a baby, or a toddler?"

Her mother-in-law laughs. "No, no. He was too busy putting electrical plugs and God knows what else in his mouth. And when he got to be about three it was Play-Doh and paste."

"Okay, thanks. Have a good time with your friend." Beckett ends the call and looks suspiciously at Castle. "I can't believe it."

"I told you," he says triumphantly, as if he has won some moral battle. "But paper, I used to eat paper. And I did suck on pencils. Makes me think I was destined to be a writer. But never my thumb."

Beckett glares at him. "Don't mock it if you haven't tried it."

"Well, I'd suck your thumb any day," he says, making a grab for her hand and pulling her onto his lap. "And other parts of your body. I love sucking on those."

"Pas devant l'enfant, Castle."

"What's that mean, Mom?"

"You know I love it when you speak French, Beckett, even if I don't know what you're saying."

"I'm sure you know exactly what I'm saying."

"I don't."

"I know exactly what you're saying when I suck—"

Beckett swats him on the arm and tries not to laugh. "Castle! I just said, 'Not in front of the baby'!"

"Uh-oh. Uh-oh."

Castle kisses her palm and beams as he holds up the framed sonogram. "This little thumb sucker? Definitely your side of the family, Beckett. You're paying for the braces."

TBC