Bo Williamson goes to Markham's office looking for him, sees the plan for "Williamson City," gets mad and smashes it. At the construction site, Bo confronts Markham about how Markham has gone behind Williamson's back by having his wife Jennifer agree to Markham's overblown plans which he would be funding. Markham jokingly offers to design Williamson's burial vault. Williamson says even if he were dead, Markham wouldn't be able to use his wife to get to his money.Back at his office, Markham tries to contact Jennifer Williamson, but she is away at a spa and is not allowed to receive any phone calls.
Williamson stops to watch one of his racehorses work out. Getting into the car to drive home he finds Markham waiting for him in the car. Country music is playing. Markham threatens him with a gun and forces him into the stables where he kills him. He then drives the body back to Williamson's house, listening to classical music in the car. He takes Williamson's partially unpacked suitcase and drives off with it.
A few days later, Columbo turns up at the Williamson City dedication looking for Jennifer Williamson. He finds her talking to Markham. Apparently Williamson's ex-wife, Goldie, had called the police to report Bo missing. Both Markham and Jennifer convince Columbo that Bo is just fine. Columbo goes to see Goldie, and she is convinced he is dead, because Bo always calls her to say he is leaving town. This time he came back for a day and disappeared again without letting know he was going. Columbo gets a call saying that Bo's car was found at the airport.
He goes to the airport, finds the car and sits in it listening to country music tapes, thinking. He notices the radio is tuned to a classical music station. Back at Williamson's house, Columbo is talking with Goldie and Jennifer, ascertaining that Bo only liked country music and never listened to anything else. He also discovers that Bo has a doctor's appointment the following day. Jennifer also tells him all about Williamson City. He also finds out that Bo had met with Markham on the day he had come back. Columbo then goes to Markham's office, grilling the secretary about his habits, and discovers Markham is a big classical music fan. She also shows him the model that Bo had destroyed and elaborates a bit about Bo's visit.
Columbo goes in search of Markham and drops in on a lecture he is giving about Egyptian tombs, and how the Egyptians wanted to keep the bodies from being discovered. Markham daringly mentions that it would be convenient to put a body in a building foundation if he ever kills anyone. Columbo questions him about his meeting with Bo the other day. He also mentions that Bo's car was found tuned to a classical music station.
At the construction site Columbo asks the foreman about the foundation and the big argument between Bo and Markham, and lets Markham know. Later, Columbo finds out from Bo's doctor that the appointment was extremely important, to replace his pacemaker battery. Later, Jennifer finds Bo's bloodstained hat near their tennis court.
Markham accuses Goldie of killing Bo because she stands to inherit 25% of the estate. Columbo discovers that Goldie had planted the bloody hat, using her own blood, to get the police looking for a murdered. It turns out the had the same blood type. Columbo then goes back to the construction site investigating the piles for the foundation. Markham offers to let Columbo dig up the pile if he can get the permits. Columbo then tells him that based on Bo's will, Jennifer would retain control of the money only if Bo's body is never found. If he is declared dead, she only gets the income from a trust. This is motive to kill him and hide the body. Columbo gets the permits to dig up the pile and starts digging. They find nothing and Columbo is disppointed.
That night, Markham goes to Bo's barn to pick up the body. He gets a flat tire and when he stops, a motorcycle cop stops and offers to help him change the flat. He asks for the key to the truck. Markham asks him to call a tow truck instead. He then goes to the building site to bury the body where he is intercepted by Columbo. Columbo then tells him how he knew Markham was encouraging him to dig, so the body was not there. He knew Markham was just waiting until after the search to put the body in a place that had already been searched.