As though that's an excuse. And this is pretty much the single worst topic they could have landed on, what with her resentment of the Doctor's tendency to cling to some misguided belief that the Master may be capable of redemption, despite everything.

And because of that, even her considerable patience is wearing thin. "The Master's motives never change! Nor does the danger he represents." She's really quite done talking to a brick wall and lets go of his hand. "And if you insist on being deaf to my advice and concern, there is no point to this conversation."