Mannix finds new evidence in the case of an embezzler he sent up the river.
Danny Brite, a nightclub comic, is being blackmailed, presumably by a soldier listed missing in Vietnam.
Mannix tries to solve the murder of a newspaper columnist, and finds himself dealing with the deceased's daughter who claims she was responsible. She was an eyewitness to the crime but when Mannix tries to get information from her, he plays psychotherapist to get the facts from her.
Assigned to find a missing scientist and the new formula he designed, Mannix gets romantically involved with the scientist's daughter.
Hired to locate building contractor Donald Jordan, Mannix gets conflicting reasons for the disappearance from Jordan's sister, wife and business partner, none of which add up. The case becomes even more complicated when Jordan turns up to assure Mannix he's all right, only to be attacked by two hoods outside the private eye's office.moreless
Lt. Paul Haber is out to nab Gang leader killer Victor Roarke, who escaped custody in the Santa Monica Mountains and has taken hostage fellow cop, Lt. Art Malcolm.
An ex-con's daughter hires Mannix to investigate who ransacked her apartment - looking for a million dollars her father supposedly stole.
The son of a gang leader is killed during a meeting with Mannix which threatens to explode into a full out gang war.
Mannix fights a conspiracy of silence to find Rose Anderson, who has been swallowed up by the underground she deserted.