“Thank you,” he says, and the words feel like they don’t fit right in his mouth. What are you supposed to say, really, when someone gives you a piece of their spirit-form? Especially under these circumstances. Shisui wishes treason came with some kind of manual. Maybe a book full of helpful hints. When plotting to overturn decades of hatred and stop a war by lying to the whole world, be careful not to offend the man giving you his teeth to wear as earrings.

Kakashi is enjoying this a hell of a lot more than he thought he would, and he had high expectations going in.

Shisui's breaths feel too loud in the quiet of the room, like they’re coming too fast. It’s like he’s panting, like he can't get enough air, and it makes his head spin. His whole body is shaking, overheated, burning up from the inside, and he has to catch himself on the edge of the sink and lean there, gasping for air, acutely, exquisitely, awfully aware of every inch of his skin. Behind him, a page turns, crinkling, and there's a quiet hum.