The private secretary of a murdered PI comes to Mannix for help. She doesn't remember much about her boss' cases, but men are trying to kill her anyway.

A man hires Mannix to track down a pedestrian he may have ran over with his car. But the only witness claims nothing happened, and men threaten Mannix figuring that he killed the pedestrian.

An assassin's bullet grazes Mannix and renders him blind, and he trains to overcome his condition and defend himself for the killer's return.