Ah but there's the thing - yes, the Master stole the Doctor's Tardis, but it could only go from the end of the universe, to the present day. How did the Master go from being released on Gallifrey to when they met him?

He didn't have the Doctor's Tardis at that stage. The writer has also (jokingly) refered to the female hand, as the Hand of the Rani. He's also said it was done to give future writers a means of bringing the Master back if they wanted to.