OCTAVIAN: Listen to me, it's important. You can't trust her.

DOCTOR: Trust who?

OCTAVIAN: River Song. You think you know her, but you don't. You don't understand who or what she is.

DOCTOR: Then tell me.

OCTAVIAN: I've told you more than I should. Now please, you have to go. It's your duty to your friends.

DOCTOR: Just tell me why she was in Stormcage?

OCTAVIAN: She killed a man. A good man. A hero to many.