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

A/N This is the second half of a two-shot that takes place in 2018 and is rated T. It's not necessary to read the first part—chapter 3 of "Hi. It's Eliot Again"—to understand this, but it couldn't hurt.

Kate Beckett is reading her son's letter to Santa Claus, the one her husband, Rick Castle, has just typed up and printed out. "You know, Castle," she says, "everything on this list is so, so—"

"Little?" he offers, propped up next to her against the headboard of their bed.

"I guess. I was thinking simple, sweet, unextravagant. Like this." She points to the first three items on the list. "He wants bedroom slippers that look like penguins. A soft blanket for Scrapple. And some pencils that say HI. I'M ELIOT. Where did he get that idea, anyway?"

Castle beams at the memory. "Didn't I tell you? We went to this cool store last week that sells nothing but pencils, every kind from all over the world. I'll go tomorrow to get those for him. They emboss them on the spot with a hand-operated machine that weighs a ton. We watched them impress some for a customer and Eliot wanted to take it apart to see how it works. You'll be happy to know I restrained him."

"I'll be even happier if you can restrain him on the drum request. I really can't cope with that yet. How about some other musical instrument, like a recorder?"

Castle makes a face. "Totally lame. Santa is not giving him a recorder."

"Fine," she sniffs. "We're starting him on piano lessons in the spring anyway. Let's just ignore the drum thing. What he really has his heart set on is these blocks. But I looked on line and everything with only letters is just so ordinary. Uninteresting. I want these blocks to be astonishing. Something he'll love, something dazzling."

Her bedmate is unusually silent.

She waits a minute, stealing a look at him. "Castle?" Still silent. "Oh. Oh." She reaches out and puts the letter on her nightstand, then takes his chin in her hand and turns his face towards hers. "You have a plan for the blocks, don't you? I can hear those synapses firing, Castle."

He smiles. "You can, huh?"

"I can feel them, too."

"Hot, aren't they?"

"Oh, very."

His hand begins creeping under her sleep shirt. "So," he says, drawing out the o until his breath is gone. "You want to put some sin in those synapses?"

"Definitely," she says, sliding slowly down, lifting the covers as she goes.

"Why, Beckett," he says in mock surprise. "Wherever are you going?"

"To check out the synapses," she says sultrily, just before she disappears beneath the sheets, "in your other head."

"Oh," he says, twitching suddenly. "Such sophisticated, uh, sophisticated, uh, wordplay."

Her voice is muffled but completely audible. "Words are not what I'm playing with here, Castle."

"Oh, good. Oh, God."

The next morning at 6:30, murmuring from the baby monitor wakes Beckett. She starts to roll over to get out of bed when a well-muscled arm pulls her back. "Don't go," Castle whispers.

"Twins, Castle," she says.

"They're not crying. Stay here."

"Mmmpf." She makes a vague attempt to leave.

"I'll make it worth your while."

This time she rolls the other direction, directly on top of him. "Now you're talkin'," she says, quite intentionally wiggling as she does.

"You want me to talk?"

"No, but I do want you to use your mouth."

"Consider it done," he says, flips her over and quickly begins to use it in ways that leave her speechless if not at all silent.

At 8:00, with Abby and Otis secure in their high chairs, more or less ingesting Cheerios, and Beckett swooning over her first cup of coffee, Castle, Eliot and Scrapple burst through the front door. "Bagels, Mom!" Eliot says, running over to hand her a bag.

"Oh, yummy," she says, giving him a hug. "Thank you. Let me guess, we're going to have bagels for breakfast?"

"I already ate," Castle says, his eyes twinkling.

"You ate?" Eliot says, surprised.

"Dad's just kidding, sweetheart," his mother says, shooting a near death glare to Castle. "Now let him help you take your jacket off, and then come back and sit down for breakfast. This is a special day, did you know?"

"Why?"

"Because Alexis and Gram are taking you and the twins out. You're going to the zoo and then to Rockefeller Center, you know why?"

"Why?"

"Because every year a family who lives in the country and has lots of trees gives a beautiful big one to Rockefeller Center to have for its Christmas tree. It's almost as tall as our building!"

"Tree there?"

"Yes, the tree is there. A long, long truck carried it over night, and it came through the tunnel and then up the street to Rockefeller Center. And you're going to see people pull it up straight and then put boards around it so it can get decorated."

"Why?"

"Why are they decorating it?"

"No. Board. Why board?"

"Oh, they have to put boards around it for people to stand on when they decorate it with lots and lots of lights, thousands of lights. The ladder isn't tall enough for that, so they put rows of boards all the way around tree for the workers. That's going to be a lot of fun for you to watch."

"I no bored with board. Ha!" Eliot exults.

Castle cracks up before Beckett does. "That's a great, great joke, Eliot."

Martha and Alexis arrive shortly after breakfast, and in a whirl of red hair gather up the three children, and set off. "Have fun, kids," Martha says, poking her head back in the door and waving at her son and daughter-in-law.

"You've got the kids, Mother."

"Not what I meant, Richard. Toodle-oo."

"Right."

"Thanks!" Beckett calls out on top of a snort.

"Want to take a shower?" Castle asks. He's wiggling his eyebrows, but she's engrossed in the paper so the gesture is lost on her.

"Already had one."

"Not with me you didn't."

"Oh," she says, looking up and smiling. "That kind of shower. My favorite kind. Okay, you're on, but then we really have to discuss these blocks for Eliot."

"Absolutely. Could take a while, though."

"The discussion or finding the blocks?"

"Neither of the above," he says, pulling her off the sofa and kissing her. "The shower."

Twice showered—thrice, on her part—and warmly dressed, they're cuddled on the loveseat in the office. "Blocks, Castle."

"You know Beckett, maybe we shouldn't be discussing blocks in the room where I write. Could affect the atmosphere. Don't want the word 'block' to hover over my laptop, give it ideas."

"I thought I gave you ideas," she says, poking him in the ribs.

"Oh, you do, you do. All kinds of ideas."

"Good. And right now we need all kinds of ideas for Eliot's blocks."

"I already have them," he says, with a certain amount of smugness. "They're perfect."

"Just when did you get these perfect ideas?" There's some challenge in her tone. "And how?"

"You know last night in bed? When you asked me if I had a plan for the blocks? Synapses?"

"Yes, Castle, I have excellent memory, short-term and long-term, and I recall every bit of that conversation. And its ancillary activities, to use your coruscating word from slightly earlier in that discussion. And actually those activities were a lot more than ancillary."

He chuckles. "True. Well, I had the beginning of the idea. One of our favorite words, really."

"Yeah?" She puts her head back and looks at him. "What?"

"Fonts."

"Fonts!" She sat up. "Of course! Mr. Sturgess. Water Street.[First appeared in chapter 5] The font guy. That's brilliant, Castle."

"Thank you, but I have to give credit to you, in part."

"Me?"

"Yeah, you. All I had at the time was the idea of talking to Tom Sturgess about who could make us some blocks in a nice fonts, but it was your inspirational undercover work that really got me thinking."

"You were thinking about fonts while we were having sex? Jesus, Castle, what—"

"Calm down, calm down. Not then, afterwards. You fell asleep—"

"Excuse me, you fell asleep. I was hoping for more."

"I admit I fell asleep. But when I woke up at 1:30 you were out cold. And since I was all revved up with nowhere to go—"

"Castle!"

"Since I was all revved up with nowhere to go, I got out of bed and came in here and started doing some research on fonts. I left the door open and I kept looking at you curled up all adorably in our little love nest."

"Oh, please."

"I did! Seriously. Anyway, here's what I came up with. We get five sets of blocks, each in a different font, made by one of Sturgess's guys. Actually fifteen sets, because we should have three complete alphabets in each font. One set in the Beckett font, one in Castle—they have a certain resemblance as you know, actually very complementary, like us. Anyway, another set in GoodDog—"

She jumps up, grabs his laptop and returns to the love seat. "I have to see what GoodDog looks like."

"Click on that folder, EB-C Blocks, and you'll see."

She does. "Oh, Castle, this is adorable. It looks kind of like a ten-year-old's printing."

"Believe it or not, there's a font called Doggy with the whole alphabet done in the shape of dachshunds, but it's just too hard to read. So we won't tell him about it."

"What else?"

"Click on the Manhattan font in the folder. Isn't that great?"

"Wait, I know this, this is from the old Woody Allen movie Manhattan, right? With skyscrapers forming part of some letters, and little windows. I love this. So will Eliot."

"Speaking of Eliot, that's my favorite, if you'll forgive my saying so."

"An Eliot font?"

"The Eliot font isn't spelled the right way, so I had another idea. Our handwriting, yours and mine. Thirteen of the blocks will have capital letters in your writing, and thirteen will be in mine. Won't that be great?"

"It will. It's fantastic, Castle. All of it. You're a genius." She leans in to kiss him. "But do you think they can do that in time? It's a really big, complicated order."

"You're kidding, right? That's exactly what our money's for, to pay someone to make that for our kid in a month." He pulls his phone out of his pocket. "I'm going to call Sturgess right now."

She gets the phone away from him before he has the chance. "That can wait, don't you think? Since for once no one else is here?"

"Oh, now that you mention it, yes. It could wait a bit."

"You know, Santa" she says, walking her fingers up his chest, "I've been a very good girl this year."

"Oh, you have. You have, Kate. An amazingly good girl this year."

"Do you think that deserves some kind of…reward?"

"I do, I do. Why don't you come with me into the next room? It's my workshop. I think you'll like it."

"Oh, I'm sure I will, Santa. I already love your toys."