What if, after Amy and Rory died, it was the last straw. The Doctor hated the Universe for what it had done to him, what it had taken away from him. Time after time he had saved it, and for what? For it to just get in trouble again. Angry and depressed, he went back in time, all the way back to the beginning. He regenerated into a little boy, a new time lord, and befriended himself. He gave himself a new name. He called himself…The Master. And he spent the rest of eternity trying to stop himself from saving the universe.