James "Brick" Davis, a struggling attorney, owes his education to a mob member named McKay, but refuses to get involved with the underworld. When his friend Eddie Buchanan is gunned down by gangster Brad Collins while on assignment for the Justice Department, Brick decides to give up the law for a career with the Department. He says goodbye to his benefactor and to his girlfriend, Jean Morgan, a singer in McKay's nightclub, and heads for training in Washington, where he immediately takes a dislike to his boss, Jeff McCord. He flirts, unsuccessfully, with Jeff's sister Kay, but earns the respect of another seasoned department man, Hugh Farrell. Despite Brick's natural aptitudes and his inside knowledge of mob activities, Jeff refuses to put him on a case even when he positively identifies Danny Leggett as one of the criminals. Jeff gives Farrell the assignment, and he's killed in the line of duty. Jeff and Brick take over the case, tracing the gang to McKay's Wisconsin lodge, with the help of Jean, who is now married to mob member Brad Collins. In a violent exchange, McKay and most of the mob are killed. Collins is still at large and wounds Brick when he attempts to warn Jean. While Brick is hospitalized, Collins kidnaps Kay and shoots Jean when he discovers she has betrayed the gang. Brick reaches her before she dies, and she discloses Collins' plan to use Kay to get through the police barriers. Brick wounds Collins fatally, and rescues Kay, who now agrees to marry him.