It's all AU.

The Master didn't feel like actually shutting himself in the TARDIS and staring at the walls. But he really wasn't up for another emotional confrontation with someone who thought he was a madman.

So, here he was sitting quietly in cafe, drinking tea, papers spread all around, buried in something much more predictable then interpersonal relationships. He was pretty sure he had math down for stabilizing the Rift. Although he hadn't had the Doctor look over it yet. But now he was sure that the current, human made, Rift Manipulator wasn't capable of the kind of fine tuning needed.

So, redesigning that it was up next. He was using just paper and pencil at the moment, but it something to do with his hand and his mind. He was pretty thoroughly engrossed.