Dale Kingston (Ross Martin) is a renown LA art critic. At the luxurious mansion of his uncle, wealthy Frank Simpson (Don Ameche), all the servants are having the day off. Dale comes in as Matthews is playing the piano, shoots him, and steals both of his uncle's most expensive paintings. He puts the body on the floor, wrapped by an electric blanket. Dale stops and stares when somebody rings the bell of the main door. The audience holds their breath because the person calling may spoil Dale's plan. However, he opens the door when he sees through the door's peering hole and it's his lover, the weak and untalented painter Tracy O'Connor (Rosanna Huffman). Tracy looks unfit for the job, because she isn't even able to look at the dead body, but she has to stay for an hour with the body getting heated up by the blanket, to delay the time of death. Meanwhile, Dale goes to the opening day of an exhibition by eccentric painter Sam Franklin (Vic Tayback). When he arrives in his flashy car, he makes Joe (Dennis Rucker), the parking boy, look for one of his cufflinks. Later, saying that there is a problem with his watch, asks several people, including Sam Franklin, what time it is, to establish the time of his alibi. At home, Tracy waits for a private security patrol to leave after a check, then fires a shot into the air, runs down the steps to her car, and rives away.
Enter Lt Frank Columbo (Peter Falk). He starts questioning aunt Edna Matthews (Kim Hunter), Frank Simpson's ex-wife, whom he had repeatedly declared to be his only mistake during his own life, as he should have never divorced her. Dale treats Edna kindly, but that's just his plot. First, he takes the couple of paintings to his own flat. Dale had given his keys to Columbo so that he could check some art book Dale had at his apartment. Columbo has fallen asleep on an armchair when Dale comes back with the paintings, wrapped on a painting portfolio. Dale wakes Columbo up, and says to him that he's carrying the work of some new painter inside. Columbo is about to see them, but Kingston doesn't want that. Columbo insists and touches the paintings, but Dale won't let him take a look at them, obviously.
Tracy is frustrated by the inability to paint well and creatively. However, Dale encourages her - although he knows that she has not enough talent. Columbo talks to the landlady (Mary Wickes), with Joe, who spent some time looking for the cufflink around the car in vain. Dale simply found it afterwards.
Some clues lead to the aunt of Frank Simpson, the ex-wife who inherited almost everything. Columbo realises that, if the aunt is accused of the murder, she won't be able to keep the money or the properties as his own, because a person guilty of murder cannot inherit anything from the murdered person.
Dale then gets rid of Tracy by meeting with her up in the hills, then bludgeoning her with a rock and dumping her body, passing her death off as a car accident. It turns out he never loved her - in fact, she was just a gullible person who happened to fall in love with him, somebody unsure of her own merits and talent - of which he thought she had none. Columbo has been pestering Dale about his relationship with Tracy, who he denies any knowledge whatsoever, especially at first.
However, some clues still lead to Dale's aunt, so Captain Wyler (Barney Phillips) and another policeman (Claude Johnson) register her home. Suddenly, they find the two paintings wrapped in cheap brown wrapping paper. They arrest the aunt.
Columbo doesn't seem satisfied with this solution. Aunt Edna is terribly upset because she looks so guilty, in spite of her innocence. He sits around a table with Dale, his aunt and Wyler. Columbo tells Wyler to check the paintings for prints. Dale says that it's only natural that there are handprints on the prints, as he must have touched them at his uncle's mansion. Columbo says that he himself had touched the paintings at Dale's apartment, in that portfolio he was trying to hide so eagerly, so if the paintings have his own prints -Columbo's-, they are the ones which he touched at Dale's apartment. Dale says that everything is a conspiration, that Columbo must have touched the paintings at Edna's apartment. Columbo shows his hands: both of them are inside gloves.
Dale is trapped, and his aunt is cleared when Columbo's prints appear.
---written by KrystelClaire