The police in Montpellier are faced with a mystery: On the beach of the nearby small town of Le Grau-du-Roi, two shot teenagers and an unconscious woman are found. While the teenagers are fighting for their lives, the woman has only suffered a rather harmless head injury – and she is in possession of a gun. What has happened here? Even when the unknown woman regains consciousness, she cannot help shed light on the darkness: she has lost her memory. Then one of the victims dies, specifically the son of the Director of the National Police. Police doctor Collete de Chadier proposes a daring plan, in which Cédric Douchet, who has recently been suspended from duty, is to keep an eye on the stranger while also helping her overcome the trauma. Reluctantly, the disillusioned investigator complies. Soon he must.