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

The work week is relatively uneventful, relatively being a key modifier when it comes to New York City homicide detectives. On Tuesday morning, Beckett, Castle, and Ryan—Espo is still on vacation—are called to the scene of what turns out not to be murder but an unfortunate combination of clumsiness and stupidity that resulted in death. With no other bodies falling, Montgomery takes advantage of the lull by putting the team on cold cases; they make some inroads without cracking anything open.

"Castle," she says groggily in bed on Wednesday night, sprawled over her fiancé with the sweat still evaporating from her naked body. "We have to tell Lanie and Espo."

"Why, Beckett," he says, pulling her face up from his chest so he can look into her eyes. "I never took you for a kiss-and-tell woman. You're planning on letting our friends know what we just did? It might take a little explaining, especially that one part. Diagramming. Visual aids."

"If I had any strength at the moment, I'd swat you for that."

"Ooh, kinky."

"Nothing kinky about it, buster," she says, and nips his nipple. "I meant we have to tell them about us. Ryan's been really great about it, but Lanie will be back tomorrow and Espo on Monday and he shouldn't have to keep the secret."

Castle winds a wavy strand of her hair around his finger. "I sense a suggestion coming."

"Glad your senses are working, though I was kind of hoping I knocked them out of you just now."

"You did, almost completely. That's why I'm waiting for your suggestion instead of making one. I'm a very suggestive guy."

She wiggles until she's comfortably plastered against him. "Dinner. Here. Sunday night. Ryan, Jenny, Lanie, Espo. You could invite them—and me. Say you want to thank us for welcoming you back. And then we'll tell them."

"When?"

"I dunno. Over dessert, I guess."

"You're going to have to stay away from me during dinner, then. And before. Lest your wandering hands reveal anything."

"My wandering hands? What about yours? One of which just wandered south."

"You want it to wander back north?"

"God, no. I want it to explore, right where it is."

"Okay then," he says, flipping her onto her back and rolling over to settle between her legs. "Just think of me as Roald Amundsen. Except the southern region that he explored was very, very cold, and this is very, very hot."

The next morning she goes into the precinct alone—they're still trying to keep up appearances—and he follows a few hours later with a tray of coffees and a bag full of pastries.

"Morning, Detectives," he says, as he offers a cup to Beckett. "Ryan? Want to join us over here? I brought high-calorie treats. And a cappuccino, which I believe is your favorite."

"Hey, thanks, Castle. What's up?" He looks into the bakery bag and takes out an almond croissant. "You buttering us up for something?"

"Despite the vast quantity of butter in these, no. I have an invitation."

"Really?" Beckett asks with convincing innocence. "To what?"

"Dinner. At my place, Sunday night. You two and Jenny and Esposito—he is coming back, isn't he? Hasn't run off to join Miami Vice or something? And Lanie."

"This a special occasion, Castle?" Beckett takes a bite of a brioche, chews contemplatively, and swallows. "Isn't your birthday on April Fool's Day? Too late for that."

Castle lowers his head as if he were looking for the right thing to say, then raises it. "I want to thank you for welcoming me back, and not torturing me about Gina, which God knows you could have done. So, can you come?"

"I'm in," Ryan says. "I'm sure Jenny is, too. Javi's coming home Friday night. You can text him."

"Me, too, Castle. That's really nice of you. I'm having lunch with Lanie today. Want me to ask her?" As if they hadn't already planned this.

"That'd be great. Thanks, Beckett."

"So, you going to help Ryan and me with these cold cases?"

"I guess."

"Well, Mister Enthusiasm, would it help you to know that there's no paperwork involved?"

"Yeah, Castle. Plus there's one case with a guy who was tied up to look like a roast pig with an apple in his mouth."

"What kind of apple?"

"I have no idea," Beckett says. "Maybe you could make that your first order of business. Find out what the apple was. Macintosh, red delicious, Fuji."

"It could be important," Castle says, and sniffs.

When they break for lunch three hours later, Castle—who has not yet isolated the type of apple that the vic's teeth had been gripping—and Ryan head out for a burger and Beckett goes to the local Thai place to meet Lanie.

"Um, Kevin," Castle says, sliding across the pleather bench in the coffee shop. "Listen, if you and Jenny would mind not mentioning to Espo and Lanie about Beckett and me? At dinner? I'd really appreciate it. Kind of awkward, you know?"

"Things going okay with you two, Castle?"

"Oh, yeah. Yeah, they are. But, early days and everything. And you know Beckett. She likes to keep things to herself."

"No kidding."

"How are things with you and Jenny? Looks pretty serious to me."

"Yeah, it is. Can I tell you something? Swear you to secrecy?"

Castle crosses his heart. "Absolutely."

"She's the one. Really the one."

"Wow, congratulations! You getting married?"

Ryan blanches and puts his hands up. "Whoa, whoa, whoa. No. I mean, I hope so. But I haven't asked her or anything."

"Don't waste a minute. Propose."

"Hey, you've been married twice. Wouldn't you be a little cautious about popping the question?"

"I suppose," Castle says, trusting that the sky will not open and a thunderbolt hurl him to the ground for his lie. He puts two fries in his mouth.

At the same time, four blocks away, his fiancée is also being less than truthful with Lanie.

"You're looking really great, Kate."

"I feel well, thanks."

The doctor waits for her friend to say something else. When she doesn't elaborate, Lanie points her salad fork at her as if it were a scalpel. "That's it? You feel well? You were moping around like a dog without a friend a couple of weeks ago and now you're all bubbly. Not like you. Something happened. Oh, no, no. I've got it. Someone happened. Spill."

"You might be right."

"Might? That means I'm on the button. Who is it? Castle! It's Castle! He came back and you're happy and you finally gave in."

"Oh, please. It's Alexander. Alex."

"Alex? Who is he? Why haven't I heard about him?"

"His mother match made."

Lanie coughs so hard she has to spit her mesclun into her napkin. "His mother? You are desperate, girl."

"Am not."

"So this Alexander Alex. What does he do? Because I can't get into a discussion about his mother, especially not while I'm eating."

"Uh, teaches. He's a teacher." Oh, if Lanie only knew what she'd learned from him in the last couple of weeks. Although she'd taught him plenty, too.

"A teacher? Where?"

Oh, shit, why hadn't she thought this through? Maybe because every time she'd tried her mind had wandered to all the talks they have, and all the laughing, and Paris, and sex. How incredible he smells. How he tells her to open her eyes when—oh, God, don't go there, mind. Don't don't don't.

"Kate?"

"What? Oh. Teaches. He teaches at Stanford, but he's here for the summer. So I think this is just a, you know, a summer fling. Fun while it lasts."

Lanie purses her lips and squints. "Yeah? That's what your mouth is saying, but not your face."

"Oh," Beckett says, trying to get control of the conversation. "Speaking of Castle. This morning he asked Ryan and me to dinner at his loft on Sunday night. He wants you and Jenny and Espo to come, too."

"What's the occasion?"

"That's exactly what I asked him. He said it was just a way to thank us for welcoming him back and not giving him any crap about Gina. He's a great cook. When I stayed there after my apartment blew up he made amazing meals for Alexis and Martha and me. What do you say?"

"I'd never turn down an invitation like that. The wine alone. And that sofa."

Oh, definitely that sofa. She picks up her wine just in time to hide her rapidly flushing cheeks. "Good, we're all set. Now, I want to hear everything about the bachelorette party and all the trouble you caused in Orlando." That's sufficient to steer Lanie away from Castle/Alex, and by the time she's through they both have to return to work. On the way to the precinct, Kate realizes how grateful she is that she has to keep up this charade for only a few more days.

When she wakes up early Sunday morning, she's alone in their bed. Wow. Their bed. She's already calling it their bed, thinking of it as their bed. She sits up, tilting her head towards his office, thinking that he might be writing, but there's no sound coming from it. She doesn't smell coffee, so he's probably not in the kitchen. Where is he?

On tiptoe, she walks out to the living room, and sees him sitting in an armchair by the window. His back is not completely towards her; she can see part of his face. He's holding his phone and smiling at a photo on it. She stays near the doorway for at least two minutes, and he hasn't scrolled to another picture. He's just looking at the same one, and seems oblivious to his surroundings. Tiptoeing again, she comes near enough so that she can she what's captivated him: her. He must have taken it quite a long time ago, because her hair is much shorter. She's sitting at her desk in the precinct with a cup of coffee in one hand and a pencil in the other, and she's laughing. How had he taken that without her realizing it? He's always playing games on his phone; she must have assumed that's what he was doing. Just didn't notice at all. There are times, and this is one of them, when Kate is taken by surprise by how much she loves Castle, and how much she's in love with him. She'd never thought it possible—nor that anyone would ever feel that way about her.

And then he touches the tip of his finger to the tiny image of her, and leaves it there. It's such an intimate gesture that it almost makes her knees buckle.

"Castle," she whispers into the back of his neck, as she puts her arms around him and clasps her hands together in the center of his chest.

He places one of his hands over her two, engulfing them. "This is one of my favorite pictures of you, Kate."

"How come?"

"'cause it was the day I really, truly, one hundred percent permanently fell in love with you. The day before I bought your ring. I wanted to tell you right then, but you would have run from the room and I'd never have seen you again."

"And now you've got me for good. You know it's for good, don't you?"

"I do."

She walks around the chair and sits down on his lap. "Remember our first time?"

"How could I forget? Fifty years from now I'll still remember it."

"Remember you'd fallen asleep and I was humming and it woke you up? You asked what it was, and I said it was an old song about us. I was watching you, a few minutes ago, while you were looking at my picture on your phone, and it made me think of another old song. It's about us, too."

She sings the first verse, so softly that he can hardly hear it.

It's very clear
Our love is here to stay.
Not for a year, but forever and a day.

Then she starts to hum with her cheek against his heart, and he thinks it might burst through his rib cage. She starts to sing again, a little louder, but still quietly. Even if the room were full of people, the only ones who could hear her would be the two of them.

In time the Rockies may crumble,
Gibraltar may tumble,
They're only made of clay
But our love is here to stay.

"That's true," he says, and kisses her.

"In a few hours, everyone will know."

"You sound a little wistful. Are you sorry or glad?"

"That everyone will know? Both. Is that crazy?"

"Nope. We don't have to do it if you're not ready. It can just be dinner."

"I'm ready. I am. It amazes me, but I am."

She's still a little nervous, though. At five-thirty, when she's showered and putting on a little makeup, her trembling hand makes mascara smear on her eyelid, and she has to start over again. Once she repairs it, she goes to see Castle, who's in the kitchen, getting a tray of hors d'oeuvres ready, and she kisses him lightly. "See you in a bit," she says, and walks out the door.

From a little bar across the street she sips on an iced tea and watches everyone arrive: first Kevin and Jenny, then Lanie, and finally Espo. It's safe for her to go back to the loft.

"Hey, Beckett," Castle says, opening the door on her knock and accepting the bottle that she'd removed from the premises less than an hour ago. "Thanks for this."

"Yo, Beckett, you're late," Espo says from behind a piece of crumbling cheese.

"Sorry, sorry. Had to park about ten blocks away. I should've just walked. And now I'm hot." She issues a faux glare to Castle. "Don't say it."

"Who, me? I wasn't going to say anything."

"That'd be a first."

The evening progresses easily, as if a group of friends were getting together for dinner just for the fun of it. Beckett and Castle are at opposite ends of the table, which eliminates the temptation of playing footsie, and each tries to give equal attention to everyone else there.

When Castle announces that it's time for dessert, Beckett offers to clear the table, but he insists that she stay put. "Well, I hope you won't mind if I get up for a moment. All that wine and the prospect of coffee means that I have to make a break for the powder room."

"Be my guest."

"I am," she says over her shoulder, as she strolls away. When she returns, she heads for the kitchen rather than the dining room, and gets Champagne from the fridge. She walks to Castle's end of the table, and gives him the bottle.

"Thanks, Beckett."

"Dom Perignon?" Lanie says, eyebrows shooting up. "You bring that, Kate?"

"Not exactly."

"This girl," Lanie says to the group, shaking her head, "is more non-responsive than ever. How can you 'not exactly' bring something?"

Kate smiles, doesn't respond, and stays where she is.

"Hey, Castle," Esposito says. "You going to open that? Don't think anyone at this table 'cept you gets to drink that more than once every five years."

"I'm opening it right now." One loud pop later and he's going round the table, stopping at each place to pour Champagne. Kate's still standing by his chair when he finishes his circuit. "Now, if you'll all lift your glasses, I have an announcement to make."

"So do I," Kate says. "It's the same one as his. We have an announcement to make."

"Here we go," Castle says, reaches into his pocket, takes out the ring and puts it on Kate's finger, just as he had in front of his mother.

They beam at each other and say, perfectly synchronized as always, "We're getting married!"

It might seem impossible for four people to create chaos, but they do. Two crystal champagne flutes land on the floor—but miraculously do not break—one chocolate mousse ends up on a lap, and all four voices are exercised at high decibels. When kisses and hugs have been fully exchanged, everyone sits down.

Espo turns to Ryan. "You owe me twenty bucks. Cough it up, bro."

"Gladly," says his partner, passing a twenty across the table.

"Gladly?" Lanie asks. "Since when do you gladly lose to him?"

"Since now," Beckett says from the edge of the chair that she's sharing with her no-longer-secret fiancé. "We'll pay Ryan back, with interest. Won't we Castle?" She kisses his ear.

"We will." He takes his wallet from his back pocket and fishes out a bill, which Kate takes from him.

"Sorry it's only a hundred, Ryan," she says, putting it in his hand. "I think we owe you more."

"What the—?" Espo bristles.

"Some people know how to keep their mouths shut," Beckett says, and lets Ryan and Jenny tell the story of the movie-theater meeting.

During the good-nights at the door, Lanie grabs Kate by the arm. "Alexander, huh? I can't believe you lied to me."

"It wasn't completely a lie. It's his middle name—and Martha was kind of the matchmaker."

When the guests are all in taxis, Kate and Castle collapse onto the sofa. "Leave the dishes," she says. "We can do them in the morning."

"That went well, don't you think?"

"It did. Very well."

"They were really surprised, even Ryan and Jenny, since they didn't know the whole story."

Kate snuggles up to him, and begins to unbutton his shirt. "Just imagine how they'll react," she coos, wrapping her hand around his ribs, "when I tell them I'm pregnant."

"You're pregnant?"

"No, that's a song for another night, Castle."

A/N Thank you so much readers, especially those who left reviews that spurred me on. I really appreciate that there are still many people who want to read Castle fan fiction, even though the show is long gone. I hope to post the last chapter of "It's For You, Castle" within the next week, and then start something new.