The text message arrives in the small hours of the morning: I need you. Isa drops everything, takes her baby daughter and heads straight to Salten. She spent the most significant days of her life at boarding school on the marshes there, days which still cast their shadow over her. Isa and her three best friends used to play the Lying Game, competing to convince people of outrageous stories. Now, after seventeen years of hiding the truth, something terrible has been found on the beach. The friends' darkest secret is about to come to light...