On board a French Navy frigate, second-in-command Jean-Louis Cazenave dies in the explosion of the diving room. The female commander uses her connections to get the best element of the criminal to quietly investigate in order to determine if it was a murder or an accident. Elodie Bradford therefore embarks aboard a warship occupied exclusively by men to conduct this investigation, which will prove to be complex and dangerous, because the main suspect is none other than the Pasha's own son and he is ready to do anything to get out of it.