Watch Doctor WhoTV-PG2005|13 seasons|Action & Adventure,Drama,Sci-Fi & FantasyPlay TrailerAdd to WatchlistSpace. For all.StoryThe Doctor is a Time Lord: a 900 year old alien with 2 hearts, part of a gifted civilization who mastered time travel. The Doctor saves planets for a living—more of a hobby actually, and the Doctor's very, very good at it.