Inspector Duke Becker and his squad are having a few weeks of peace and quiet when a case is brought to the squad by Detective Michelle Goldman. A fellow Detective has been investigating a baffling homicide, and Goldman believes the Special Investigations Unit, Homicide, might be able to help out. When another homicide is discovered along with a second strange object left behind by the killer, Inspector Becker and his squad move into high gear. Soon the squad figures out that this killer is identifying with the classic movie Casablanca. What is the killer's motive, how does he pick out his victims, and who is the killer are questions Becker will need to answer if he is going to stop the killings.