We follow the daily activities of two London bobbies, veteran Police Constable George Dixon (Jack Warner) and rookie Police Constable Andy Mitchell (Jimmy Hanley). Meanwhile, young hoods Tom (Sir Dirk Bogarde) and Spud (Patric Doonan) plan a series of robberies with Tom's girl Diana (Peggy Evans), a discontented beauty, as an inside worker. But in their second crime, one of our heroes is shot, setting off a citywide manhunt. The killer is clever, but will he outsmart himself?