A violent explosion occurs in the bay of Sète. A worried mother goes looking for her son, Maxime. Her life is turned upside down when the body of woman, her own sister whom she hasn't seen in over 15 years, is found on a beach.
Chloé tries to understand why her son is in custody. An unidentified woman, who was on one of the wrecked boats, was found on the beach. But who is she?
Chloé and her mother, Marianne, find Anna in a coma. Chloé wants to understand what happened to her sister. Why did she come back to Sète after 17 years? Why did she hide who she really was from Maxime?