The Master smirks. She's not backing away, though she should. What a perfect companion the Doctor chose this time.

"For one thing, I can smell it all over you." And he takes another whiff, sighing a little. Almost wistfully. "I'm a Time Lord, you think I don't know what a TARDIS smells like? The Time Vortex?"

He pauses for effect, then adds, almost as an afterthought: "Even if the Doctor hadn't told me."