Re: Where do I start?
Well the Doctor would say he "Borrowed" his TARDIS.
To expand somewhat as well as soon as the Doctor becomes part of events he then can't go back. As it would be crossing his own timeline.
On the continent of wild endeavour in the mountains of solace and solitude there stood the citadel of the time lords, the oldest and most mighty race in the universe looking down on the galaxies below sworn never to interfere only to watch.