I didn't say that! [Martha's voice is cracking, and she's close to tears.] But there's a difference between wondering what's going on and being there. I lived it, Doctor, and I relive it almost every night. It wasn't just the Earth, it wasn't knowing what the Toclafane really were, it was knowing that he would have done that to every planet if he had the chance. I knew there was only one way to stop it for good, and I had to. It wasn't that I didn't trust you - I didn't trust him to stay imprisoned.

[She looks down, because she can't quite bring herself to meet his eyes.]

UNIT never cared much about what I did. They used it to threaten me at first, to get me to come quietly and do what they wanted. But when they started questioning me, the only thing they ever asked about was you. They wanted to know about you. And I never told them a thing. I stopped talking for months rather than say anything.