The Master stopped, turned, and stared. "He did what? Has he completely lost his mind?"
That being a rhetorical question, as the Master was quite certain that the other being discussed had. Really, basing his rule on a paradox? And using the only TARDIS to hold it?
"How do I recognize that one, so I can keep away from him? I'd rather not find out if stupidity is catching, especially seeing as it's one of, well, me. Us. Something." He paused. "Is he one of the ones of us taking pot-shots at Jack?"