The show opens with Leslie Williams, an attorney, gluing letters cut from a magazine to a piece of paper and an envelope. She then takes a tape of her husband's voice and cuts it to use a part that says, "They've got me." In the next scene, her husband Paul arrives home, not realizing she is there. Leslie surprises him and shoots him. She then picks up the lamp that was knocked over and replaces the mail he brought in. Then she wraps his body up and puts it in the trunk of her car. She gets his briefcase and gets in the car, moving the seat forward before she drives away. She dumps his body in the ocean and then mails the letter to herself. When she gets home, she calls a friend named Pat and asks her to call her office the next day at 12:15 to remind her to put their tennis date on her calendar.
The next day, Leslie is in court defending a client against a lawsuit. A man comes into the courtroom and tells Leslie that he has been unable to track down her husband. She says she will file a missing persons report after lunch. Court recesses for lunch, and Leslie returns to her office to outline a settlement plan for the plaintiff. While she's there, Pat calls and says, "One word: tennis. Don't forget," then hangs up. Leslie pretends to be upset, then tells her assistant to call the police because the man on the phone says he has her husband.
Back at Leslie's house, they find the letter that she sent. The police are working on setting up a tap on the phone. Columbo arrives at the house to tell the police that Paul's car was found. He hangs around for awhile, then asks to see the ransom note and the envelope. One of the other officers tells him that the kidnappers sent instructions and a map showing where Mrs. Williams is supposed to drop the money. The instructions said they will call that night.
Columbo wanders into the next room, and Mrs. Williams follows him. He asks her where the bathroom is, and she sends him upstairs with directions. When he comes back down, Leslie decides to go into the kitchen to make everyone dinner. Columbo asks her if she has any live-in servants, and she says that she does, but her housekeeper has been on vacation for the past week so she's been alone.
Later that night, the call comes in. Leslie had rigged another phone to make the call automatically and play back the tape of her husband's voice saying "They've got me." He also says they want $300,000 and tells her to follow the instructions. She then hangs up the phone and gets very distressed. She goes up to lie down. Columbo tells another officer that he thinks it strange that Leslie never asked her husband if he was all right.
The next day, a man from the bank brings the money to Leslie's office. He tells Leslie that in order to get all the cash available, he had to sell off all her stocks at a considerable loss. She tells him that this is no time to worry about money. After he leaves, the police tell her they brought a bag for the money, but she already has one. She asks them to leave so she can get changed, and when they leave, she switches the bag with one in her locker. She gets in her plane and Columbo and the other officers get into a helicopter to follow her. En route to the drop location, Leslie drops a tracking device out the window of the plane. Later, she drops the empty bag out the window. The police land on the scene and find the empty bag. They assume that the kidnappers got the money and left before they could get there.
When they return, the other officers leave, but Columbo stays behind. He checks Leslie's locker, but the bag with the money has been removed.
Leslie goes home and hides the bag in a secret door in her closet. When she turns around, there is a girl seated in her room. The girl turns out to be Paul's daughter Margaret from a previous marriage. She came straight home from Switzerland when she heard about her father. It is clear that Margaret and Leslie do not get along.
The next morning, Margaret is watching television when Leslie comes downstairs. The movie Margaret is watching is about a woman who is trying to buy life insurance for her husband because she wants to kill him.
Leslie goes to prepare a client for trial. While she is there, Mr. Carlson, one of the agents on the case, and Columbo enter the room. Carlson tells Leslie that they found her husband dead, and she almost faints. She decides to go home, and Columbo remarks to Carlson that she all of a sudden lost her composure when the whole time, she's been very collected. Carlson gets defensive and tells Columbo to leave her alone.
Back at her house, the doctor gives Leslie some sleeping pills. The police and the doctor all leave, and Leslie throws the pills into the fire. Margaret, who was supposed to be upstairs sleeping, comes down and finds Leslie walking around the living room humming softly to herself. Leslie does not see her.
Columbo stands in the back of the crowd at the funeral. As the funeral comes to an end, Margaret accuses Leslie of wanting her father dead and then slaps her. Leslie sees Columbo but just walks away and gets in the car. Columbo tells Margaret to let him know if there is anything he can do and that he is always available. Someone comes up to get her then, and she leaves.
Back at her house, Leslie's friend Pat tells her to kick Margaret out. Then all of Leslie's friends leave, and she calls Margaret to come down and talk to her. She tells Margaret that she had to close her trust account in order to pay the ransom and as a result, Margaret's allowance will have to be reduced significantly. She advises Margaret to try to find a job.
The next morning, Columbo has an appointment with Leslie. While in her office, he sees her phone, which is obviously very high-tech. He says he's fascinated by it, and he writes down the name of it, claiming he wants to try to get one for his office. He then tells her that some of the details of the kidnapping are bothering him. He mentions the bag that was used in the drop, saying it seems very unlikely that a kidnapper who was afraid of being caught would take the time to take the money out of the bag before he took off. Leslie says that maybe the kidnapper looked in the bag, saw the money, and then took it out because he was nervous and not thinking rationally. Columbo then says that because of the angle of the bullet entering Paul's body, the killer must have been sitting down. He does a reenactment of it, and Leslie has a flashback to when she killed Paul. She gets upset and asks for a glass of water, which Columbo gets for her. She asks him to continue, and he tells her that the gun that was used was a .22 revolver. He thinks the reason that gun was selected is because the killer did not want any trace of the crime in the room where it happened. The .22 would not have enough speed to go all the way through the body. Columbo goes on to say that all the small things he noticed, when put together, make the kidnapping seem staged. He says that Paul was probably killed by someone he knew, and the kidnapping story was created simply to throw off the police. He asks her to tell him all about her husband so maybe he can figure out who might have had a motive to kill Paul. Leslie tells him she doesn't agree with his theory, but she will do anything she can to help him.
She takes Columbo flying in her plane, where she tries to teach him how to fly the plane. He asks if Paul had any enemies, but she says no and that he was a very good man. He also asks if Paul ever cheated on her, but she says he would never do that. When they get back to the airport, Columbo says that her description of her husband reminded him of his cousin Ralph, who was so good at everything that he was an incredible bore. Columbo says that he was such a bore and so perfect at everything that there were times he felt like killing Ralph. Leslie excuses herself and goes to change her clothes.
Columbo goes to a diner to get something to eat. While he's waiting for his food, Margaret comes in to talk to him. She tells Columbo that Paul came to see her in Switzerland and said that Leslie wanted him to turn control of his firm over to her. She didn't want a divorce, but she wanted to lead separate lives, sharing the house but nothing more. He threatened to kick Leslie out, and Margaret says she thinks that's why he was killed. Columbo tells Margaret that she has no evidence, and that her assumptions don't prove anything. He then says the only way that Leslie could have done it was if she killed him first, then staged the kidnapping. Margaret is about to leave, but Columbo mumbles something about the position of the car seat. Margaret comes back, and he tells her that the car seat had been moved forward in her father's car, and he also tells her that they never found the car keys. She says that maybe whoever last drove the car still has the keys. Margaret goes home, where Leslie is taking a nap on the sofa. She calls Columbo, and he comes to the house. When he arrives, he wakes Leslie, and Margaret shows him the keys that she found. Columbo tells her that he knows there was a locksmith at the house and that she made duplicate copies of all the keys. The keys she is holding are not her father's keys. Margaret tries to slap him, but he grabs her arm and tells her never to do that again. She pulls loose and runs upstairs. As Columbo goes to leave, Leslie thanks him for straightening Margaret out. He says it was all he could do because he couldn't have her "accused of murder on the wrong evidence."
Later, Leslie is having a drink, and Margaret comes in and accuses her again. Leslie tells her that if she continues to make trouble, she will not get another penny of her father's money. Margaret runs out of the room.
In her office the next day, Columbo calls. While she thinks she's on the phone with him, however, he walks into her office. He got a phone like hers and rigged it up to call her at a certain time and play the tape of him speaking. He says it shows that the alleged kidnappers' call could have come from her office. She tells him he has no case, and he says that he's been taken off the case. He says goodbye to her and leaves.
When Leslie gets home that night, Margaret is in the same chair that Leslie was sitting in when she killed Paul and holding a gun. Margaret fires a blank at her, then holds the gun on her. She fires another blank, and Leslie says that there's nothing in the gun. Margaret runs and hides, and Leslie finds her in the closet. Margaret agrees to go back to Switzerland if Leslie gives back her trust fund.
The next day, Leslie takes Margaret to the airport to send her back to Switzerland. After she says goodbye, she sees Columbo. She buys him a drink and while they're talking, he says that he thought he'd never get her. Then he thought of the ransom money. He had to find a way to get her to use the ransom money. He says her problem is that she has no conscience, so it never occurred to her that not many people will take money to forget about a murder. A man brings Margaret's suitcase with the money to the table. He opens it up and tells Leslie that the whole thing was set up with Margaret. He told Margaret that if she really wanted to get Leslie, she would have to find a way to get her to use the ransom money. Leslie knows she is caught, and Columbo asks the police to take her downtown.