The Master shrugged. "No one seems to think I'm sane, anyway, so what does it matter?" He didn't actually meet Romana's gaze, watching the Doctor instead.
"Actually, Jack's probably died again since - you and I both killed him this time, isn't that just the sweetest thing you could do for me? - and I'd killed him before, so that adds two more deaths to that total. If you're really wanting to count Jack's dying, seeing as he doesn't stay dead."
He wasn't about to dignify the Doctor's actual question with an answer. Well, not a real one, anyway.
"What makes you think I don't have a back-up plan, anyway, Doctor? Think killing me over and over's going to stop me? Or even make you feel better?" There was a challenge in his voice, and in his expression - though he was banking on either the Doctor being tired of all the death, or Romana stopping the Doctor. He hoped.