Odessa Berken, Chief Warrant Officer of the Navy, investigates a disturbing disappearance at the naval base of Brest. Frédéric Le Gall, chief of a marine unit, announces a suspicious absentee, Yassin Rhaled, 23 years old. The following day, Yassin's body is fished out of the ocean. The autopsy conducted by Samuel Delaunay leaves no doubt: the young man was murdered. The first suspect is Nathan Berken, the victim's best friend and Odessa's brother with whom she has a stormy relationship. On the military port, Odessa's arrival does not go unnoticed, as an elegant woman with a fiery temperament who does not hesitate to speak her mind.