On a sunny morning, Alison, her half-sister Kitty and friend Vanessa went to school. And an hour later there was a monstrous car accident, in which Alison miraculously survived, but Vanessa died, and Kitty was left severely disabled. Now, 15 years later, Kitty is still unable to speak and suffers memory lapses, and art teacher Alison leads a quiet life and tries in vain to forget what happened that morning. However, when Alison, despite the fears, accepts the offer to run courses for prisoners in the local prison, something strange and frightening begins to happen...