The Doctor gets every ally he can find to stop Davros and the Daleks.
So, the Earth was stolen…
Donna sees how much a single left turn could have changed everything.
Martha, now working for UNIT, gets the Doctor’s help to look into a mysterious car exhaust system that seems to kill people.
The Doctor gains a new companion that he’s met before in the incomparable Donna Noble.
The Doctor finds himself aboard a space-based Titanic around Christmas time.