Aurore Garnier, a police officer, has been obsessed with the abduction of her 5-year-old sister Clara. Their mother, Isabelle, died while handing over the ransom. 20 years later, their grandparents are about to sell the family estate and favor their grandson, Frédéric. Jacques, the father, has remarried and has a teenage daughter, Thelma. During a murder case - the death of Paco Vasquez - Aurore finds photos of a young woman resembling her sister at the victim's home. She traces Clara Ivaldi in Italy, but the woman fiercely denies being her sister. She is intrigued by Aurore's story.