A fifteen-year-old British teenager, who calls herself Zoe, writes letters on the back of her geography homework, sitting in a garden shed at midnight. The one-way missives are going to Stu Harris, a Texas death-row convict. In the letters, Zoe confesses her own guilt--she killed someone too. Her humorous and naive letters gradually reveal her struggle with her dysfunctional family and her turbulent and destructive romance with a classmate and his older brother.