A charred body is found in the debris of a building obviously torched by an arsonist and Shannon uncovers a trail that leads to a local hood who used to know Shannon when they were boys. Shannon is assigned to the arson squad when several uninhabited and abandoned buildings are torched.

Norm White's personal problems nearly jeopardises the good work put in by his partner, Shannon, and the other cops in tracking down a band of robbers who have been preying on banks with expertise. Norm is unable to carry out his duties well as he is in two minds about letting his wife, Patty, take up a job to help make ends meet.

The investigation of a black politician's murder is complicated by the involvement of the syndicate. Shannon's boyhood friend and adult nemesis, Bunky James (Ron O'Neal), is released from jail to help him investigate the politician's murder which looks like an execution by terrorists.

Shannon is on the take, but it is only to break a gambling operation. It started with the suicide of a police officer suspected of having received bribes. Shannon seizes this opportunity to cultivate friends among the wheeler-dealers in town. One particular person is Burt Harvey, who is happy to make an "investment" In return for information. With the help of Connie, the dead officer's girlfriend, Shannon and Moraga set out to wipe out the entire Illegal actions.

Shannon is assigned to work with Judy, a policewoman, who resents his help. Shannon joins the lady detective working on a series of rape cases.

Ivy Horton tries to kill her ex-husband and mental patient, Alex, to protect herself and her daughter. Even though the man is threatening his family he can't be arrested until he commits a crime.

Shannon learns that Paul, his father-in-law, is the victim of loan sharks. He has been pressed to commit a crime to repay a due.

Jack Shannon becomes a detective on the San Francisco police force, and his first case sends him back to the Big Apple. He has to defend himself against a charge that he, as a New York cop, strong-armed a witness. Jack's move is put on hold when the NYPD questions his conduct on his last case.