It's all AU.

The Doctor wandered back to the TARDIS, mended from his latest encounter with a less than sane Master. Which he didn't regret. He was. Thoughtful. Worried for him. It occurred to him, that in a lot of ways, the situation here was similar to the one that had finally broken his Master enough to want to change. Trapped in a situation he couldn't control, and unable to run away from the consequences of his actions. Who knew which way this other Master's break down would go?

Well, at least this place was minus the hordes of Daleks.