Parts: 1 (45-minute)
Writer: Gareth Roberts
Airdate: 12 June 2010
Production Code: n/a

Doctor: eleventh
Companions: Amy

Story: When the TARDIS attempts to land in Essex, something goes terribly wrong, and an explosion ejects the Doctor from the TARDIS before it dematerializes again, with only Amy on board. Unable to retrieve the TARDIS, the Doctor decides to make the best of a bad situation, and answers an ad to become the new lodger of a nearby apartment. His new flatmate, Craig, is a pleasant and humorous fellow, an everyday bloke who secretly pines away for his best friend Sophie. But in a corner of Craig's ceiling, an odd kind of rot is spreading, and the Doctor suspects that it oughtn't be touched...

The Doctor gradually begins to realize that whatever interfered with the TARDIS' materialization is occupying the flat upstairs. Unbeknownst to him or Craig, a mysterious figure has been luring unsuspecting strangers into the upper flat, after which they are never seen again. And if the Doctor isn't quick to discover who or what is in the flat, the out-of-control TARDIS, unable to materialize, may be flung into the space-time vortex, casting Amy adrift forever...