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

She's going back to work this morning, and woke more than half an hour before her alarm was set to go off. Castle is sound asleep on his side, and she's lying in bed looking at him. In the last two days he talked her off the ledge so many times. She has thanked him twice as many, maybe three, but it will never be enough. She's still astonished by what a calming influence he can be. The voice of reason, even. If someone had told her that a couple of years ago, she'd have hooted.

Through these two days and nights they've talked and talked and talked about Simmons and Bracken. They've talked about other things, too, but what meant and means the most is how he'd brought her around on the subject of kids. His last plea was what had really done it, right before they'd gone to sleep, and she goes over it again, recalling how he'd phrased it: "If you die before me," he'd said softly, "which I can't believe I'm even saying." He'd stopped. Even in the low light she'd been able to see his Adam's apple move as he'd swallowed hard. "If you die before I do, Kate, don't you know how much it would help me to cope with that loss, with that crippling grief, if we had a child, or children? That I would have this living, breathing, talking, laughing, crying, singing, jumping, smart-as-a-whip, magnificent part of you to love and raise? And what if I die before you? Would you rather be on your own, or would you rather be loving and raising that living, breathing, magnificent creature whom we created together?"

She'd looked into those blue, blue eyes of his–which had looked even bluer than usual because of the periwinkle duvet on the bed–for a long time. He'd waited for her to say something, looking alternately terrified and hopeful. She didn't want him to be terrified. His argument was simple and in many ways obvious, but it was also lovingly persuasive and perfect. "You're right, Castle," she'd said at last, caressing his cheek with the backs of her fingers. "I want the living, breathing, magnificent creature that's part of you."

"And you."

"And me. But not this instant."

He'd nudged her with his knee and chuckled. "That's good, because I'm way too tired to create anything right this instant."

She slips out of bed now, goes into the bathroom, and shuts the door. Consciously and unconsciously she avoids looking at the tub. She'd tried to soak in it last night, but the whole notion of a tub, even one that bears no resemblance to the one that Simmons had repeatedly shoved her head into, had made her queasy. She has time for a bath this morning, but she chooses the shower. The tub can wait. She'll make her way back to the tub some day.

She puts on her makeup and gets dressed in the bathroom so as not to wake him. This whole thing has taken just as much out of him as it has her, and it probably cost him more emotionally than it has her. She decides to takes the cheerful, wiggly Gummy for a turn around the block. Castle is staying home today and will give him a good run later in the park. Blocks of snow and ice are everywhere, and not likely to melt soon. When they get home she puts the dog's kibble in his bowl and creeps to the bedroom to check on Castle. He's turned over onto his stomach now, with his hand spread out on her pillow as if he were stroking her hair, but he's still asleep. She blows him a kiss, and before leaving home puts a hot pink Post-it note on the coffeemaker. "If Gummy tells you he hasn't had breakfast, he's fibbing. xoxo"

Even though she stops to get a take-out coffee, she's 15 minutes early to work, and not surprised that the boys aren't here yet. She's equally unsurprised that Gates is, so after stowing her bag in her desk drawer she heads for the captain's office. "Good morning, Sir."

"Good morning," her boss says, with a genuine smile. "It's nice to have you back."

"Thank you. I, uh, wanted to thank you for the extra time off. I didn't think I needed it, but I did."

"You went through quite an ordeal, Detective Beckett. I wish that I could have persuaded you not to go."

"It was my choice." Not to mention–and she doesn't–that, despite everything, she now has a line on Bracken.

"Yes, well, I'm still sorry. I'm glad that you're here ahead of the others. I have something for you." She opens a folder and removes an envelope which she holds between her thumb and index finger. "Forensics found this in their sweep of the house. It's addressed to Mister Castle, but it's your handwriting. I'm pretty sure I know what it is, and I thought that you might want it." She passes it to her. "No one has to know about this."

She closes her eyes for a moment, the memory of writing the letter flickering against her lids like an old movie running through a projector. "Thank you," she says, feeling shaky enough that she puts a hand on the corner of the desk to steady herself as she gets up. "I appreciate that. I'd better get to work."

"You're welcome," the captain says, then bows her head over the papers in front of her.

As soon as she's at her desk she shuts the envelope in a zippered pocket inside her purse. She thinks of it throughout the day; it feels as if it's radioactive, as if it might break the needle on a Geiger counter.

Castle sends her a text at least once hour. The first is, "Did you have breakfast?"

"It's Baker's birthday," she types in return. "There are doughnuts. DD glazed, number one on your personal hit parade."

Later on it's, "Want a snack?"

"No, thanks, I'm fine."

At noon he asks, "Should I bring you some lunch?"

"I'm sort of sharing a pizza with the boys."

Next he sends a video of Gummy dragging her bra out of the laundry basket and trotting around the loft with it in his mouth. "The dog has excellent taste," Castle writes. "Notice that he chose the purple lacy one."

Then, "It started to snow again. How about I show up with a Thermos of tea? I mean the good stuff, made with loose leaves, not those bags."

To which she answers, "It's okay, thanks. I'll be home soon."

Twenty minutes later it's, "What would you like for dinner?"

"Anything you'd like to make," she writes. "Or order. Have you noticed how food-centric your texts are? BTW, you better not have let Gummy chew up my bra. It's almost brand-new."

"Don't worry. I swapped him a biscuit for your bra."

She understands that he's trying to divert her, trying not to be over-protective, and it's sweet. It even works, some of the time. Half an hour before the end of shift her he's back again. "The weather sucks. May I pick you up and drive you home?"

She's said no to his other offers, and she's happy to accept this one, happy knowing that it will make him happy, too. "YES! Thank you. I'll be downstairs at 4:01."

"You're so precise, Beckett. Very sexy."

"You're lucky no one's reading over my shoulder, Castle."

At 3:59 she says good night to Espo and Ryan, and walks down the stairs as a tiny nod to exercise. She's fidgety and cooped-up and the letter is burning through the leather of her bag and the wool of her coat. At 4:01–precisely, she thinks–she pushes open the front door of the precinct and there's Castle, standing next to the car, which is parked at the curb.

"Hey."

"Hey."

"How was your day?" he asks, as he drives to Broome Street far more cautiously than usual, the road slick with ice.

"No one got murdered, at least not in our neighborhood. So I guess that makes it a good day."

"I guess it does," he says, hooking her little finger with his. "Did you really eat one of Baker's birthday doughnuts?"

"A bite."

"How about the pizza?"

"A slice, I had a slice."

"Uh, huh. Well, good thing I'm making your absolutely favorite dinner."

There's something in that almost offhand gesture, that reflection of his generosity and kindness, that makes her want to weep. She doesn't say anything, can't really, and after a minute he takes a quick sidelong glance at her. "Are you all right, Kate?"

"Yeah." She tilts to her left, as much as she can in the confines of her seatbelt, and leans her head against his shoulder. "Know what my absolutely favorite part of my absolutely favorite dinner is?"

"Sauteed chanterelles?"

"No. The guy who's cooking them."

"I'd kiss you right now, but I'm afraid of crashing the car."

"When we get home, then."

"Yes. When we get home."

Except when they get home, she kisses him before he can kiss her, right up against the wall.

"Wow," he says afterwards. "That was incredible. You kissed me as if your life depended on it."

"It did. My life does depends on you, Castle. You've been my lifeline for a long time, especially since Berryville. And the last few days, my God. Everything you do for me, Castle. It's unquantifiable. Could we sit down for a minute, please? I have something I want to show you."

It's seldom that he's speechless, but her little speech, outburst, whatever it was, has made him so. She takes his hand and walks him to the sofa with her. After getting the letter from her bag, she pulls her legs up under her so that she can sit at a right angle to him, with her knees grazing his thighs.

"When I was in that room, alone, the other night–. When I was waiting to meet Simmons, though I didn't know that's who it was, I was afraid I wouldn't get out of there alive. Not certain of it, but I figured there was at least a fifty-fifty chance that I'd die. I wanted to be able to say goodbye to you, and the only way I could was to write a letter. I knew that I had very little time, so it had to be short. As soon as I'd done it, I hid it behind a vent. I pricked my finger and smeared a few drops of blood on the vent, to ensure that someone from CSU would look there." She stops to gather both her breath and her senses.

"I got out, but CSU did search later. They found the letter and Gates got them to give it to her. She returned it to me today. Recognized my handwriting. So here it is." She thrusts it at him, but he draws back.

"Don't you want it, Castle?"

"No."

"Why? It's for you. I wrote it to you. It's yours."

"Why don't I? Because I don't think I can bear knowing what was going through your mind then."

"But I'm alive, Castle. I'm here. We're here. Please? I have a hard time knowing how to thank you for everything, and I thought that this was my last shot at it. Please."

Reluctantly, he takes the envelope, pulls the flap up, and removes the letter. But before he can unfold it, he gives it back to her. "I can't," he says, his voice cracking. "You'll have to read it to me."

She'd never foreseen this reaction, this emotional collapse. She'd hoped that it would help him to know that his love for her had kept her strong all the way to the end. That was what she'd wanted. She'll read it aloud to him, then.

"Dear Castle,

"Thank you for your overwhelming and limitless love. You saw me at my worst and gave me your best. You forgave. You opened my heart and my mind and my eyes to possibilities that I either never knew existed or that I'd turned away from years ago. You made me laugh. You taught me the value of silliness. You got me to talk. We could talk about anything, couldn't we? And we had so much fun. You helped me find my way out of the dark. You gave me joy. You gave me the most fragile thing there is, hope, and made it seem indestructible.

"I love you. If I die tonight, my last thought will be of you, my last breath will be for you. Don't grieve for me too long. You brought happiness back to me. Let your last gift to me be that you will be happy again. My heart will be full of you forever. Kate"

She knows that he's crying even before she looks up and sees his face. He rubs his hands hard against his eyes, then leans over and very gently takes the letter from her hand, folds it up, puts it back in the envelope, and leaves the room.

He's been gone for a long time, and she begins to fret. Should she go after him, or let him be? Castle can be deeply introspective–something that very few people realize–but he rarely wants to be alone unless he's writing. Even then, he's glad if she comes into his office and reads while he works. "See, Beckett?" he'd said one recent, rainy Sunday, when he triumphantly finished a chapter. "Even as a mute muse, you are my inspiration."

She goes after him.

The closet door in the office is wide open. The safe is in there, and he's standing over it, head down, his hand resting on top.

"Castle?" When he doesn't move or answer, she closes the gap between them and lightly presses her palm between his shoulder blades. It's one of the places on his body that she most loves. "Is something wrong?"

"I put it–." He clears his throat. "I put your letter in the safe. For safekeeping. It's in the safe."

"I'm sorry. I'm really sorry. I didn't think that this would upset you."

He turns around so fast that her hand flies off his back, and he's hugging her so hard that it hurts. She doesn't care. Eventually she coughs because she can't get enough air to breathe properly, and he loosens his grip.

"It's not the letter," he says, his breath warm against her scalp. "It's knowing that you thought that you were at the end. It's knowing that what you decided to do with the last minutes of your life was to write me a letter. It's thinking that you might believe that I'm not aware of how much you love me. Every part of me is aware of that, every minute. But when you wrote it down, it–. I am overwhelmed by your love, Kate."

It takes a few moments for her to be certain that she can speak. "So you're going to keep the letter in the safe?"

"Yes. And we will be safe. We will get Bracken, but we will be safe. And every day we will come home together, and I will know that the only love letter that I care about is waiting here, safe at home."

A/N Thank you for reading; thank you double for leaving reviews that spur me on. I will be on the road from Friday through Tuesday, and probably won't be able to update until a week from today.