Season 4 debuts with a collision involving the TARDIS and a spacecraft replica of the Titanic. Kylie Minogue plays a waitress who helps the Doctor stand against a race of android angels.
Part 1 of 2. The Doctor becomes John Smith, a human schoolteacher, to hide from alien villains in 1913 England, with Martha assuming the role of maid and the Time Lord's caretaker.
Cute creatures cause trouble for the team, and repressed attractions manifest as a result. Meanwhile, Magnus must perform an autopsy on a grandfather who believed he was an abnormal.
Rory maintains a vigil for Amy while the Doctor is trapped in the Pandorica, and the key to restoring the universe may lie with a little girl who still believes in stars in the 5th-season finale.
Dr. Rush defies orders to interface with the Destiny's computer in a bid to control the ship's flight path, which puts Col. Young in a difficult position. Meanwhile, Lt. Scott, Eli, Chloe and Greer explore a planet's underground ruins.
Arthur finds himself in danger when he comes to the rescue of Sophia and her father, Aulfric. Merlin tries to find out more about them and what they are up to.