During World War II, Steve Rogers is a sickly man from Brooklyn who's transformed into super-soldier Captain America to aid in the war effort. Rogers must stop the Red Skull – Adolf Hitler's ruthless head of weaponry, and the leader of an organization that intends to use a mysterious device of untold powers for world domination.
The 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.