Owning a TARDIS is brilliant! With it, the Doctor can travel to any place, or any time, he chooses. The possibilities are endless!
Except, that’s not entirely true. There are some places he’s been before he can never return to, for fear that his very presence might create a paradox that could tear the universe, or even just one small corner of it, apart.
What use is a time machine you can’t use to save the people you care about the most?
Amy and Rory must live out their lives in the past. He’ll never see them again.