AIRDATE: June 12,2010
COMPANION: Amy Pond
VILLIANS/ALIENS/MONSTERS: Auto Pilot
OTHER CHARACTERS: Craig Owens, Sophie, Steven, Sean, Micheal, Sandra, Clubber
LOCATION: Aickman Road
The TARDIS lands in Colchester, not where it was programmed to go, and The Doctor steps out on to the grass; the TARDIS immediately takes off, unplanned, separating him and Amy. Meanwhile, passers-by are seen being lured into a nearby house by a voice seeking help, from the intercom at its front door. The door opens and they ascend the staircase to the first floor, entering the room which lies there; flashing lights are seen and screams heard emerging from the room.
The Doctor knocks on the front door and rents the room which has been advertised by Craig Owens (Corden) in a local newsagent; he pays £3000 in cash, which Craig accepts. Meanwhile, it becomes clear that Craig's close friend Sophie (Haggard) is a regular visitor and even has two sets of keys to the house. The Doctor quickly becomes integrated into the household, cooking for Craig and playing football with great success for Craig's pub five a side football team. A mysterious stain has also appeared in the ceiling of Craig's parlour, and when Craig touches it, he becomes extremely weak; The Doctor revives him with very strong tea and successfully substitutes for him at a planning meeting in the call centre where Craig and Sophie work.
The Doctor has become aware that the first floor room may not be all it appears to be, and has set up an apparatus in his room; he is in contact with Amy through an earpiece. His experiences on Earth are punctuated by increasingly frequent "time-loop" events, in which his own time is separated from those around him, who are unknowingly involved in repetitive events, which also affect Amy in the TARDIS.
Craig, however, has become jealous of the increasingly popular Doctor, since Sophie in particular has expressed enthusiasm, and tells the Doctor to leave the house, throwing his £3000 back at him. The Doctor refuses; while this ensues, Sophie comes to the house and lets herself in, leaving one of her sets of keys in the door- she is attracted by the voice from the first floor room, and ascends the stairs. Realising this, after performing an psychic technique involving head-butting that informs Craig of his alien nature, the Doctor and Craig hurry upstairs to rescue her; concurrently, Amy realises from studying the house's blueprints within the TARDIS that the building is only one storey tall, and that the "upstairs flat" is in fact a spaceship disguised by a perception filter.
After preventing Sophie from being forced to activate the ship's console (which resembles the TARDIS central column), the emergency AI hologram (who takes the form of Craig's seldom-seen neighbour among others) informs the Doctor that the ship had crashed and the crew killed; it has rebuilt itself and attempted to fly away by luring in humans to act as pilots, however the human minds weren't sufficient and burned out, leaving only husks. Recognising the Doctor as a suitable pilot, the ship tries to pull him in. Knowing he cannot pilot the ship safely (as it would destroy the entire solar system in the process), the Doctor realises that the ship had only lured in people who wanted to escape or leave somewhere, hence why it hadn't attempted to lure Craig before (nor Sophie, until the Doctor motivated her to better herself). After admitting their love for each other, both Craig and Sophie touch the panel's activator, causing the ship's engines to shut down and the ship to implode. The Doctor, Craig and Sophie escape in time to see the top floor of the house, and the spaceship within, disappear.
Afterwards, the Doctor says his goodbyes to the newly together Craig and Sophie, who give him his set of keys to the flat as a parting gift. Back in the TARDIS the Doctor travels back in time a week and instructs Amy to leave the note in the newsagents that directed him to Craig's flat in the first place. However, whilst rooting in the pocket of his discarded blazer for a pen, Amy discovers the ring Rory had given her before he was erased from time; its presence appears to unsettle her. It is revealed that there is another crack in the wall behind Craig's fridge, which glows ominously.