The TV series "Thirteen" is a British detective thriller about the sudden return of a missing girl. Ivy Moxham is presumed dead. The thirteen-year-old girl is mourned by her devastated parents and sister, who have long learned to live without her. But unexpectedly, 13 years later, the now grown-up Ivy appears on the doorstep of her childhood home. She tells a horrifying story about being held captive in a basement all this time. However, the police find numerous inconsistencies in the girl's account.