She considers them both in silence, sizing them up, simmering too, thinking of all the tick marks against their names in her head –can't decide who you're angrier at: the one for sabotaging the TARDIS and dumping you with the Tetraps later; or the other for taking off and leaving you with that–

And then she bursts out with the first thing that comes to her mind, which is:

"What in the name of Rassilon's privy happened to you two?"

Which is a stupid question; the answer, obviously, is regeneration; but wasn't the Master in that borrowed human body last time, and she'd only just left the Doctor, and—

Oh, this is a timeline tangle and no mistake.