The Doctor along with Amy Pond and Rory Williams are kidnapped by Daleks. The Ponds are going through a rough time, they are on the verge of divorcing. Amy is at a photo shoot when Rory turns up with divorce papers which Amy signs then Rory leaves.
The three companions are taken to the Parliament of the Daleks where the The Doctor is ordered to go down to the planet below with the companions to turn off the force field on the planet. What has prompted the Daleks to be concerned is noise coming from the planet which they, the Daleks believe is a threat to them.
The planet below is an Asylum for battle-scarred Daleks that are too ill to go into battle. The Daleks want the companions to fully turn off the force field so that they can destroy the planet to prevent the escape of those Daleks on the planet. The Daleks say they will teleport them off before they destroy the planet but The Doctor doesn't trust them, he needs to get off the planet before they destroy the planet.
The Doctor is assisted by communication by someone called Oswin Oswald who had been onboard the Alaska when it crashed. The Doctor and Amy Pond find the Alaska and all the inhabitents are dead but they suddently come to life.
Oswin had managed to hide in the encampment by making souffles but the Doctor is puzzled where she gets the eggs and milk from. When the Doctor goes off to rescue her, he discovers that Oswin is in fact, a Dalek and in her mind, she is still Oswin. When the Doctor tells Oswin the truth, she can't quite accept the truth but does eventually come round to it and agree to help the companions to get off the planet and back to safety. Oswin also removes knowledge of the Doctor and the companion from the Dalek Hive computer and when the Doctor gets back to the Dalek mothership, none of them know who he is and so escapes. The Daleks destroy the planet.
The episode marked a surprise guest appearance by Jenna Coleman who would later be cast as the next companion, Clara.