His eyes widen, very slightly. Wei Ying has not told her.

He understands, when he thinks about it, why Wei Ying might not mention him. But he cannot be certain, now, that Wei Ying has told her any of it, and if he has chosen to keep silent, Lan Wangji will not betray him.

"I... fought against them," he says, finally. "I believed they were wrong, in what they were trying to do. I failed. I was unable to stop them, but they felt it necessary that I be punished for the attempt."