Police Captain Filan is sent to assume command of the District Office of a port city on the Black Sea. There is evidence that the port authority and the local government are under the control of a criminal organization, and Captain Filan has been given the secret assignment of investigating the suspected corruption. Within days of Captain Filan's arrival, the Chief of Customs, Graube, is murdered. It is clear to Captain Filan that this was a warning to him, and he decides that it is now not just an assignment, but a mission of personal honor to both find the murderer and to uncover the inner workings of the corruption in the local government. Captain Filan is joined by Graube's widow, Vika, and the two begin a shrewd and intense investigation, which will lead them down a path with many twists and turns, as they uncover a series of clues that they hope will lead them to the leader of the underground criminal organization that controls the city.