At Melbourne's Russell Street Police Headquarters, Sgt. "Bluey" Hills, unable to work within the existing police squads, oversees Department B. They're assigned cases other departments could not readily solve by conventional means, with Hills applying his unconventional methods to bring about their resolution. Bluey's investigations are supported by newly assigned Gary Dawson, long-time cohort Monica Rourke, and undercover officer Reg Truscott, who spends his time ostensibly working as a small-time burglar, and supplying Bluey with information on the activities of local criminals.