The Doctor (Matt Smith), Amy (Karen Gillan), and Rory (Arthur Darvill) land on an alien structure in space that looks like a seedy 1980s Earth hotel. A Minotaur-like creature (Spencer Wilding) consumes everyone trapped there and is itself trapped, in pain, and suicidal. The rooms contain the greatest fears of the people trapped in them. No-one can escape and the hotel layout is constantly changing. Also, the TARDIS disappears.
Trapped with them are Joe (Daniel Pirrie), Howie (Dmitri Leonidas), and Rita (Amara Karan), who have been taken out of their lives by the automated system and fed to the creature. Amy and the Doctor are drawn to two specific rooms, where they face their own fears. The Doctor figures out that the victims are frightened into falling back on their faith, which allows the creature to possess them. It is Amy’s trust in the Doctor that is challenged. She becomes possessed.
As the creature comes for her, the Doctor and the others grab her and take her back to the room. Inside, they find young Amelia Pond (Caitlin Blackwood) waiting for the Doctor to return. The Doctor convinces Amy that he is not a hero, which breaks her blind trust in him. The creature collapses and the hotel is revealed to be part of a huge simulation. The Doctor takes a survivor named Gibbis (David Walliams) home and drops off Amy and Rory in London. Travelling with him is too dangerous.
Displayed among the photos of past victims are a Sontaran, a Judoon, a Sister of Plenitude, and a Tritovore. The Minotaur-creature is related to the Nimon, and there are Weeping Angels. The Doctor’s Room 11 is filled with the sound of the TARDIS cloister bell. Rory seems to have nothing to fear, after travelling with the Doctor, dying, and losing Amy more than once. Introduced are the Tovolians, a race of cowardly aliens who survive by being easily conquered. Gibbis was a kind of giant mole and Matt Smith thought he was hilarious in his makeup. David Walliams had previously been considered to play the Doctor. The episode seemed to refer to Stanley Kubrick’s The Shining, and 1984, in which rooms contain your worst fears.