Congressman Paul Mackey is being courted by Governor James Montgomery, who is planning to run for President to be his running mate. Now Oscar Finch, a man with whom he has an unusual relationship with, is hoping that he can get a cabinet position. Oscar is constantly being called by Paul Staplin, who wants him for something. Finch then grabs his gun and goes to his office, takes the powder out of one of the bullets and places it on a piece of foil and burns it and places the residue in another piece of foil. Then proceeds to meet Staplin. It seems that Staplin is in trouble with the law and he wants Finch to destroy the key piece of evidence before they get it. Finch, not wanting to risk what he and Mackey have going refuses. Staplin then threatens to reveal that 21 years when he was in trouble, Staplin helped him by "coercing" a young lawyer in the D.A.'s office, Mackey, to destroy some evidence against him. Finch then pulls out the gun and shoots Staplin. He then takes out the foil and blows the powder residue on to his hands to make it appear that he shot the gun. He then places the gun in Staplin's hand and leaves. The next day, the police led by Columbo investigate the "suicide", but he doesn't think it was, for one thing no blood fell on top of the gun and the blood that did fall didn't smear the gun. He then learns that Staplin called Finch the night he died, he then goes to Finch's office to talk to him, who claims that Staplin did call him but he didn't talk to him. Columbo then learns that on the night of Staplin's death he faxed to his wife, who was in Hawaii, a joke and that it was only the first part and he didn't get to fax the second part, which makes him doubt that it was suicide. Columbo eventually discovers the link between, Staplin, Finch, and Mackey; 21 years ago Finch's firm represented him when he was in trouble, and Mackey was working for the D.A. and somehow the evidence against Staplin disappeared. Columbo confronts Finch about this, but cause of the circumstantial nature of evidence is unfazed. Columbo later receives a report from his sergeant and confronts Finch again, this time he reveals that one of the pieces of cheese that Staplin was snacking on the night he died was not eaten by him. Columbo with Finch's dental x-rays claioms that he was the one who ate it and when they get a shape of his jaw, they will have all the evidence they need.