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

It never would have happened if he hadn't left her there alone. And if Montgomery hadn't forced her to take time off and forbidden her to return for ten days. So really, blame it on them. Especially Castle.

Kate Beckett has been staying in Rick Castle's loft for almost two weeks, ever since her apartment had blown up, taking virtually everything but her with it, courtesy of that homicidal madman Scott Dunn. She's been here alone for the last four days because Castle's mother, Martha, is on some kind of 24-karat "spiritual" retreat in New Mexico and Castle has taken his daughter, Alexis, skiing in Colorado for what is laughably known as spring vacation. Laughably because the temperature hasn't gone above freezing in weeks and it's snowing so hard at the moment that Beckett can barely see across the street. He had of course invited her to come with them to Aspen; she had of course declined. Demurred, more like it. Saw all kinds of looming disasters, none of them involving the actual skiing.

She had intended to find some semi-affordable hotel room for her enforced paid leave, and to do some serious apartment-hunting while she was there, but Castle had insisted she stay at the loft. "We're going to be away, Beckett. God knows who might try to break in, but not with you there. You're a far better deterrent than the unbelievably expensive alarm system we have."

"Is that supposed to be a compliment?" she'd asked, eyes flaring.

"Damn straight it is," he'd said firmly.

So, okay, he had talked her into it. The most comfortable bed of her three decades on Earth might also have played a role, as might the guest suite's (yes, suite's) shower and tub. And many other enticing things, not least his collection of DVDs and, better yet, books. He had told her to make herself at home in his office, to read anything she wanted. And that's just it: she wants almost everything there. Castle's wide-ranging appetite for food is matched by that for books.

And that is where the trouble started. With the books.

She hadn't looked at a single potential apartment, and it's because of those damn, seductive books. Nineteenth-century French, English, Russian, and American novels. Histories. Biographies of world leaders and adventurers and oddball inventors and saints. Metaphysical poets. Who knew he liked poetry? But he does. Naturally he does. It makes perfect sense to her now: she has learned more about him in 72 hours with his books than she had in a year and a half of him following her around to write one (and more to come) of his own. Not one of the books is for show. Not one has an uncracked spine. Every one of them has been read, some numerous times. Occasionally she'd found notes that he had scribbled in the margins, questions or observations.

She'd make a sandwich in his kitchen—which was stocked with enough food for the entire building—and a cup of coffee, come in and choose a short stack of books, sit on the sofa and start reading. Maybe lie down and read. Get up for another cup of coffee, look through a few more books. And then yesterday, day three of her blissfully silent confinement, she had started glancing furtively at his chair—not his armchair, which she had already tried out and given her seal of approval—but the chair behind his desk. As if looking at if were some kind of crime, or violation of his privacy, which was ridiculous since he'd told her to make herself at home here. Besides, he violated her privacy on a fairly regular basis.

There's something about that chair. It's his chair chair. The one where he sits when he's writing, when he's writing about her. Not her, but her-ish. And them-ish. It's not as if she can't see something of the two of them in Nikki and Rook; she's not that deeply in denial. And this morning, with the snow coming down hard, she finally succumbs to its strange allure and sits down in it. Spins around, puts her feet on the desk. Plays with all the things on the desk, channeling Castle. It's when she leans back in it, stretches out at a certain angle, that his collection of James Bond books—the dozen novels and two collections of short stories—appears directly in her sightline. She runs her eyes over the titles, beginning with the first, Casino Royale, which is on the far left because, no surprise, Castle has arranged them chronologically. That gets her thinking about gadgets. Gadgets, gizmos, all the spy toys that appeal to Castle. Does he have any? Are there things in this very room? This would be the place for them, wouldn't it? He must have. With his imagination and so much money, he must.

Suddenly she pushes the chair back, puts her feet on the floor, and whips around to look at the enormous photo behind his desk. She doesn't have Castle's self-proclaimed Spidey senses but she has something as good or better: the eye of a detective, both intuitive and trained, and patience. Lots of patience. It takes her more than an hour to find it, and another thirty minutes to work it out, but she does. The photo is concealing a panel, and what appears to be a tiny, natural crack in the top of his desk is not natural at all. When she inserts the thin blade of an antique letter opener letter in the crack and applies just the right amount of pressure, the panel moves soundlessly to reveal a room behind it. A very large room. So help her, she gasps. And then she steps in.

There must be motion sensors, because as soon as she enters recessed lights in the ceiling come on. There are no windows, but the overhead lighting is more than adequate, and there are several standing lamps and desk lamps in the space, which she figures must be at least 450 square feet. The furniture is understated but elegant. A large cabinet with shelving on either side of two doors is flush against one of the shorter walls. A closet, maybe? She pulls on the two small knobs and discovers a queen-sized Murphy bed that glides down silently at the press of a small button. She presses it again, and the bed—fitted out with sheets and a thermal blanket—returns to the upright position. She pushes the cabinet doors shut and looks around. It's a panic room, a gorgeous panic room.

There is another door in the far corner, and it opens onto a small powder room with a basket of towels under the basin and a wall-mounted cabinet stocked with soap, toilet paper, disposable razors, toothbrushes, and toiletries. Whoa, wait a minute. Most of them are obviously Alexis's (zit cream, even though the kid has perfect skin), Martha's (anti-aging serum) and his (after shave), but a couple are hers. Not hers as in they belong to her, but ones she uses. Jo Malone pear and freesia body cream? How the hell did he know about that? Noboby knows about that. Is he stalking her toiletries? This is too creepy. Oh, oh. Oh. She remembers. There was that case, had to be six months ago, a woman strangled in her bedroom and there was a jar of that cream on the table right next to her. She'd mumbled something about that being what she uses and Castle must have heard. All the times she was sure he hadn't been listening or paying any kind of attention, he must have been. Still, why did he buy it and put it in here, along with her cherry-scented shampoo? Because she's staying in the loft? It makes no sense. Unless. Unless he thinks there's some possibility that she will be there when they might need the panic room and he wants her to feel at home? It's really kind of sweet. His perfect-host status just went a little higher.

She's poked around enough, feels a little embarrassed. She looks at her watch (bless you, Castle, for saving it from the ruins of the apartment and for getting it fixed, she thinks) and is startled to see how much time has gone by. No wonder she's hungry. She turns to go; the panel is closed. Dammit. How does it open? There's no key, obviously. Must be a computer lock of some kind in here. She looks around. Nothing. No blinking light, no black box, nothing. Zilch. Maybe in the desk? There's a desk with a laptop and a couple of drawers. She's mildly anxious as she turns on the computer, slightly more anxious as she sees that it's password protected. She runs through a number of possibilities; nothing works. Castle is too savvy to use an easily-cracked password.

"Merde!" Shouting out loud relieves her stress a little. She does it again. "Merde!" She wonders what prompted her to swear in French. Ah, because she'd just been reading Sartre's No Exit in his office, even though it was in English. She chuckles lightly, and then the worry returns. She's stuck in this room. Nice as it is, she's stuck in this freaking room and she's beginning to feel claustrophobic. She's going to have to swallow her pride and call Castle, confess to having been snooping around and to having been stupid enough not to realize that the door would close behind her. She'll never hear the end of it. Suck it up, Kate, she mutters, as she reaches into her back pocket for her phone.

"Merde" is not nearly strong enough now. "Fuck!" she screams. Her phone isn't in her pocket, it's in his office.