Ah, but the Doctor's underestimating the Master's ability to adapt. Adapt or die, really. And if he's to get something more out of it than what he's letting on, well. That's for him to know and the Doctor to find out later.

The Doctor's peering at him as if he's a puzzle to be figured out, and the Master has to admit that he does love this, has always loved this.

And it will never get old.

"Why do you think you're still alive?" He looks in at the Doctor calmly, in no particular hurry. "After all, I'm sure Sobek doesn't really need two Time Lords, does he?"