Police Squad!

Frank investigates a district judge's courtroom after it is booby-trapped with a powerful explosive. The main suspect is a recently paroled ex-convict with a history of similar bombings. Upon questioning the bomber's ex-wife, Frank and Ed find she's more interested in getting charity than the fact that her ex-husband may be up to his old tricks. Frank and Ed discover the bomber has a showgirl girlfriend on the side. She has the perfect alibi for her boyfriend, but Frank and Ed wonder if she's really just covering for him.

The mob sets up an "insurance" scam that threatens several businesses and residents. Frank and Nordberg go to investigate. After a dance instructor is beaten up, they set up their own shop - a key-making and locksmith store - and go undercover. When the mob stops by to offer them "insurance", Frank dismisses their threats and the mob strikes their store. Frank ends up having the key to stopping the crime wave, largely because of the key-making and locksmith shop he and Nordberg set up.

A struggling comedian owes money to the owner of a nightclub. When his body is discovered at the bottom of a cliff in a car crash, all the clues point to suicide. It is later discovered that the comedian was also a police informant on a drug ring he infiltrated at his nightclub. Frank steps in and takes the place of the deceased at the nightclub in order to gather more clues.