Popular shock jock Max Hudson is doing his morning radio show when he gets a phone call. Across town at Max's house, his wife, Jeanette, has been found dead. In an apparent accident, Jeanette left the gas from her bedroom fireplace on, took a nap, and died of asphyxiation.
A month later, Jeanette's sister, Linda, goes to Monk for help. Linda thinks that Max Hudson was somehow responsible for Jeanette's death. Monk agrees to investigate, and after some snooping at Max's house, Monk agrees with Linda that Jeanette's death looks suspicious, and that Max was probably involved. But Max was on the air at the time Jeanette died. How could he have done it?
Monk decides to pay Max a visit at the radio station. Max insists that Monk ask any questions on the air, where Monk becomes an easy target for mockery by Max and his obnoxious radio sidekicks. Max denies any involvement in his wife's death, but Monk leaves the station certain of Max's guilt.
Max's house has a security system, and the morning Jeanette died, records show that all windows and doors were closed and locked, except for one eight-inch ventilation window in the basement. But who or what could have fit through such a window? Monk and the gang go to one of Max's public appearances to find out, where they establish that not even Little Willie, a little person and one of Max's loyal sidekicks, could have fit through the ventilation window. Max confides in Monk that Jeanette's death wasn't really an accident, but that it was suicide. Monk still isn't buying it. He knows it was murder.
Monk and Natalie go back to the studio during one of Max's radio shows, and Monk, armed with some old jokes from his neighbor Kevin Dorfman, is itching to go on the air. Monk asks a few questions, and then starts telling his horrible jokes. Max turns on Monk, and starts making jokes about Trudy's death. Monk loses his cool and physically attacks Max before leaving the studio. After the confrontation, Monk is more determined than ever to nail Max.
Monk returns to Max's house, where he notices something. A tiny dog is walking around with a shoe, the same type of shoe that Monk found missing from Max's closet when he was first investigating. The dog's owner, Max's neighbor, explains that Max recently took care of the dog while the neighbor was on vacation, and with that, Monk has solved the case!
Monk calls Capt. Stottlemeyer to Max's house, where they wait for Max to return home from his radio show. When Max arrives, Monk demonstrates how Max murdered his wife. Monk has a police officer go to Max's neighbor's house with a stereo, and cues the officer to play a recording of Max's radio show from the day of Jeanette's death. When the dog hears Max say the catch phrase 'Jiggle me timbers!' on the recording, the dog walks next door to Max's house, enters through the ventilation window, goes to the bedroom where Jeanette died, and turns on the gas. Max trained his neighbor's dog to murder his wife! Unfortunately for Max, the dog took one of his shoes on his way out of the house, and Monk made the connection. The case is closed, and Max Hudson is arrested. Max Hudson may be number one on the radio, but he learned the hard way that Adrian Monk is number one when it comes to solving crime!