She really doesn't like the sound of that.

There's something else she doesn't like either.

"What's going on here?" she says. "Shouldn't you," the Master, "be trying to destroy him," the Doctor, "or have you reformed as well as regenerated?"

Because they are being far, far too—well, chummy would be overstating it, but the last time the three of them were all in one place, they certainly didn't waste much time standing around bantering.