He would have thought that she'd want the light on. No, she said. She wanted darkness. Darkness and warmth. She gave him enough details to understand, and his writer's mind filled in the rest. How she'd woken supine and strapped down, the lights glaring down at her. How chilly it had been in the makeshift surgical suite.

So they turned out the lights and threw extra blankets on the bed, and made the bed into a sort of cave. She snuggled up tight against him, the little spoon to his big spoon, and buried herself under the blankets so deeply that he could see nothing but a few locks of hair.

He would have thought she'd be a long time falling asleep, but quite soon there was only warmth and darkness and sound-asleep breathing. He was glad of it, and a bit envious. No blankets piled high or beloved body against his would banish his chill, for it came from within.

He'd welcomed it at the time, as he'd welcomed it the first time he'd felt it. That first time—when Alexis was taken and the one thing he had to go on was whatever information that driver had. It was as if a key had turned, tumblers falling into place, and his terror and panic had vanished as cold suffused him like smoke. Making it possible to do what needed to be done. That first time had been over and done so quickly that he hadn't had time to dwell on it or wonder what made it possible.

Now, though. Now, there could be no question it was a part of him and probably always had been, waiting for the right circumstances. When it had come over him, standing there in the precinct and realizing that only sheer ruthlessness and practicality would save Kate and destroy Tyson, he'd welcomed it back like an old friend.

He wondered: Was it just a tool to be used when necessary? Could he put it away and never think of it again? Now that it was there and an acknowledged part of himself, would it lurk benignly in his soul or metastasize until he was no longer the man he'd been?

He slipped out of bed, taking care not to disturb Kate, but he needn't have worried. She was out, and only let out a faint snuffle as a sign that she'd felt him leave. He padded into the bathroom and without turning on the light splashed some water on his face and stared into the mirror. He'd thought he might look different after arranging to have a man killed, but he looked the same as ever. Then again, he saw what he'd done as no different from putting down a rabid dog. No, what troubled him was not what he'd done but his ability to do such things. Father's son, he thought, not for the first time.

Something in the mirror.

He blinked, squinted hard, told himself it was just Boba Fett. But it wasn't. Behind his own reflection, another reflection of himself. The sort of ghost image you see looking at a dark window in a bright room. Him, but not him. It was pale and gaunt, with eyes like glacial ice. Looking at the image, he thought of grade school science experiments with one plant raised in sunlight and the other in darkness.

It's over, he told it. You're done now. You can go.

The ghost image smiled; it showed no teeth but there was something sharklike about the smile all the same. I'll be here when you need me again.

If I need you, he told it. If. Bracken's behind bars and Tyson and Nieman are dead. If.

A shake of the head in reply. A bit pitying, a bit scornful, but mostly just matter-of-fact.

And of course he knew why. He would need it again, when whoever had stolen two months of his life came back. When he had—or let himself find—answers.

All right. But until then, stay buried.

It made no answer but moved toward him. Unthreateningly, unhurriedly. Like an old friend. It came out of the mirror and passed through him, and holy Christ it was cold…

"Castle?" Kate's voice.

He blinked, looked around. He was in their bed. Perhaps he'd never left it. It was still dark, but he could see her face, feel her gaze on him.

"You were talking in your sleep," she said.

"Was I?"

"You said you were cold. I stole the blankets again, didn't I?"

He made no reply but just wrapped her in his arms again. In a little while they were both warm, and deep asleep.