The Doctor and Amy arrive in Appletown, an idyllic Colorado town where townsfolk go peacefully about their routines. But when two more strangers arrive, things begin to change. As death falls from the sky, the Doctor is trapped. The TARDIS is damaged, and the Doctor finds he is living backwards through time. With Amy being hunted through the streets of the Doctor's own future and getting farther away with every passing second, he must unravel the secrets of Appletown before time runs out.