During the first season of the series Joe Mannix worked for a large Los Angeles detective agency called Intertect, which was the planned original title of the show. His superior was Lew Wickersham, played by Joseph Campanella with the agency featuring the use of computers to help solve crimes. As opposed to the other employees who must wear dark suits and sit in rows of desks with only one piece of paper allowed to be on their desk at one time, Mannix belongs to the classic American detective archetype and thus usually ignores the computers' solutions, disobeys his boss's orders and sets out to do things his own way. He wears plaid sport coats and has his own office that he keeps sloppy between his assignments. Lew has cameras in all the rooms of Intertect monitoring the performance of his employees and providing instant feedback through intercoms in the room. Unlike the other Intertect operatives, Mannix attempts to block the camera with a coat rack and insults Lew, comparing him to Big Brother.
To improve the ratings of the show, Desilu head Lucille Ball and the producer Bruce Geller brought in some changes making the show similar to other private eye shows. Lucille Ball thought the computers were too high tech and beyond comprehension for the average viewer of the time and had them removed.
From the second season on, Mannix worked on his own with the assistance of his loyal secretary Peggy Fair, a police officer's widow played by Gail Fisher – one of the first African-American actresses to have a regular series role. (Wikipedia)