Cécile Bellange is a worried mother. Her 18-year-old daughter Annabelle and her friend Dorothée left Paris for a summer holiday in England, but the only contact from them is a postcard sent from Rudyard Lake in Staffordshire three months ago. Meanwhile, in England, brothers Martin and James Stuart find a note from two French girls, inviting the finder to meet them at Rudyard Lake. Their enquiries lead them to Mandalay, a guesthouse where the girls stayed, and its owner, creepy Mr Barker. Arriving in England, Cécile Bellange meets Detective Joanna Piercy, who is looking into the girls' disappearance. Soon Joanna must answer two important questions: what is the anxious Mr Barker trying to hide, and where are Annabelle and Dorothée?