Electronics expert Harold Van Wick has wired his estate-home with closed-circuit television cameras and video recorders. His costly fascination with gadgetry raises the ire of his frugal mother-in-law, who owns the firm where Van Wick is the chief executive. His mother-in-law orders him to resign and threatens to reveal his philandering ways that she has discovered through a private detective. So, Van Wick schemes to murder his mother-in-law on tape while a recorded image of an empty study is being received by the guard monitoring the estate's rooms on television screens at the gate to the Van Wick estate; then, Van Wick timer-sets the recording of the murder to play while he is at a social function, thus giving him an alibi. He forces open a window and lays footprints outside to make the murder look like the deed of a burglar. But Lieutenant Columbo, the super-intelligent detective of many fetishes and a rumpled raincoat, suspects Van Wick and asks incessant questions as he probes the murder and tries to link it to Van Wick.