Would you risk your life to save a stranger? A local schoolgirl has been missing for weeks when Margot Lewis, agony aunt of the 'Dear Amy' advice column, receives a letter: Dear Amy, I've been kidnapped by a strange man. I don't know where I am. Please help me, Bethan Avery This must be a hoax. Because Bethan Avery is another young girl, who went missing twenty years ago. As more letters arrive, Margot becomes consumed by finding the sender and - unlike the police - convinced that the girls' disappearances are connected. Solving this puzzle could save someone's life - but could it also cost Margot her own?