Nothing, she thinks. Nothing would fool me. And she can't recognize it for the piece of arrogance it is, only curse herself for having been born so excellent.

"If I were another Master," she says, "I wouldn't wait to be outwitted -- I'd sweep in to attack you both, where I knew you both would be, before you could form your alliance to threaten me."

Another, wiser Master might not, after having seen them fight, and imagining how they would fight together. Another Master might watch and wait. She can't recognize that, either.