It was easy to think in steps, from travel to breaking-and-entering, easy to be reassured by the steadiness of his teacher's voice. But within the house were people who should never have been involved with him at all, children and household staff, not a ninja in the lot. Sasuke lifted his hand to the sash of the window, ready to force entry, and then --

Had to stop.

"I've never," he started, fumbled his words and stopped to rephrase. I've never killed someone who wasn't also trying to kill me. "I don't know how -- how I should --"

He looked back at Obito, anguish poorly-hidden.