Parts: 1 (65-minute)
Writer: Steven Moffat
Airdate: 03 April 2010
Production Code: n/a

Doctor: eleventh
Companion: Amy

Megalomaniac of the Week: the Atraxi, Prisoner Zero

Story: In a little girl's house, voices whisper behind a crack in the wall. There's a room, with something lurking inside, that nobody ever notices. And the entire Earth is in danger from it, as well as the beings that want to track it down.

The Doctor's all ready to jump in and help, but he's only just regenerated and he hasn't quite got the hang of his new body yet. Plus the TARDIS is rebuilding and won't let him in. And the sonic screwdriver is on the fritz. With no resources but his wits, and no backup except for his new friend Amy and some brave local villagers, the Doctor has twenty minutes to prevent the Earth from being incinerated...