The Doctor discovers that the disturbance is linked to the top floor of a house, but he can't investigate it directly without being noticed. He decides to rent a room on the ground floor from , a shy office worker who is secretly in love with his best friend, Sophie.
: Craig places his hands on the controls and focuses on his love for Sophie. [S5E11] The Lodger
The Doctor eventually realizes that the "upstairs flat" doesn't actually exist; it is a that crashed on Earth. The ship is automated and trying to find a pilot to fly it home, but because humans are biologically incompatible, the ship’s engines burn them up every time they try to take the controls. The Resolution The Doctor discovers that the disturbance is linked
: The ship’s "perception filter" shatters, and it departs safely without harming anyone. The Doctor eventually realizes that the "upstairs flat"