"Useless?" The Master looks affronted in the extreme. "Before I got here, I'd become Prime Minister of Great Britain and taken over planet Earth using a satellite network, mass hypnotism, a laser screwdriver, a self-built paradox machine and the human race from the End of the Universe. I'll go kiss Rassilon's chapped arse if you can claim to have done something more impressive in your recent timeline."

He glances over at the Doctor in regard to the question. "And yes. We can be quite, quite sure. We couldn't be more sure."