Klara is a 33-year-old interpreter in the French Army. After experiencing the horrors of war in Syria, she's transferred to Nice as part of Operation Sentinel, and there with her sister Tania and their mother, she tries to rebuild her life. But one evening, Tania is found half-dead on the beach after going to a nightclub; she had been raped and beaten. Klara resolves to do everything to find the attackers and avenge their crime against her sister. Her merciless hunt leads her to Yvan Kadnikov, the son of a powerful Russian oligarch of the French Riviera.
