Kate Ashcombe receives a call from her husband, former police commissioner Harry Ashcombe, that her beloved dog is sick. She drives along the wet highway heading for the vet's office, talking to Harry on the phone. Up ahead, Harry is setting up a skid block directly in her path. He gets out of the way as Kate comes along, hits the skid block, and goes off a nearby cliff.
Three days later, Ashcombe calls a press conference when his wife hasn't turned up. He sends out his best wishes to his wife and assures her that they are still trying to find them. Monk has heard about it and Sharona gets the two of them into the press conference playing on Monk's reputation. After the conference, Monk asks Stottlemeyer what he can do to help and says that he knows what it means to lose a wife. Stottlemeyer reluctantly takes Monk to see Ashcombe, who claims that he's glad to have the assistance.
The next day, a woman named Dolly Flint wakes up in her car on an empty stretch of beach. She sees another car nearby, partially buried beneath a mudslide, and Kate's corpse behind the wheel.
While the police secure the crime scene, Stottlemeyer talks with Dolly, who insists that Kate's spirit summoned her there in her sleep. Dolly insists that she never met Ashcombe or his wife, but is clearly eager to play on the attention to get publicity for her business as a consulting psychic. Stottlemeyer, who has arrested Dolly in the past as a bunco artist, has Disher escort her away from the crime scene. Monk and Sharona arrive on the road above and Stottlemeyer, noticing them, goes up to see why they're there. Monk has noticed drag marks on the highway and insists that the car couldn't have gone off the road the way it did if it had skidded because of the rain. The captain dismisses it as inconsequential and says that Dolly is there. Monk insists that psychics aren't real, but Sharona is convinced and Stottlemeyer admits that psychics have helped the police in the past.
Ashcombe arrives to identify his wife's body and Stottlemeyer goes down to meet him. Meanwhile, Monk notices an intact tree where Kate should have gone off the road. Meanwhile, Ashcombe breaks into tears on cue when he see Kate's body. When Dolly comes over, Ashcombe thanks her for leading them to Kate's body.
Monk finally comes down to the crash site and stands on a board so he doesn't touch the wet sand. Doll comes over and Monk stares intently at her, and Sharona talks about how impressed she is with the psychic's ability. She agrees to give Dolly a private reading and notes that she'll be raising her rates since she found Kate's body. Dolly drives off, splattering wet sand on Monk's pants, and he goes into a panic. Despite that, he notices that dolly had to move the car seat forward when she got in.
Later, Stottlemeyer returns to his office after the inquest and finds Monk and Sharona waiting for him. The captain is less than thrilled to discover that Monk has been cleaning his desk. He tells Monk that the coroner ruled Kate's death an accident and suggests that his friend is jealous. Monk irritably insists that Dolly has failed to determine anything useful in hundreds of cases, but Stottlemeyer believes that she has an authentic psychic experience in this case. He shows Monk and Sharona a photo from a traffic camera showing Dolly driving her car alone through a red light right before she discovered Kate's body.
Monk and Sharona go to the memorial at Ashcombe's house and Monk gives Harry a book of poems. Ashcombe takes Monk's hand in both of his, sending Monk into a panic. He runs upstairs and ends up in the master bathroom, and discovers that Ashcombe is packing up Kate's things already. Monk also spots a pair of boots with wet sand on them. There's another box in the bathroom and Monk looks at it as he cleans his hands. Ashcombe comes in and tells Monk that he should have gone to the guest bathroom. The former commissioner talks about how Kate's father gave them the house and it was too large for the two of them, and figures that Monk would understand why he wants to pack away Kate's things. Monk sadly admits that he hasn't thrown any of Trudy's things away, even the hair from her hairbrush.
Monk goes downstairs and goes through Ashcombe's mail. Sharona comes over and objects, and Monk insists that he's not stealing anything. He finds a small package with the name Jennie Zeppetelli on it, and smells expensive perfume from it. The package has been declined six times and Monk figures that Jennie was Ashcombe's former girlfriend and he broke it off with her.
Later, Monk and Sharona go to see Jennie at her home. He realizes that Jennie was with Ashcombe for five years, and Jennie says that she finally left Ashcombe because she knew that he would never leave his wife and lose access to her money. Since they broke up four months ago, Ashcombe has been calling her and sending her gifts. Monk realizes that Jennie doesn't think that Kate's death was an accident and she warns them that her former lover is a dangerous man.
When they go back to Monks' apartment, Monk cleans out his refrigerator and insists that Ashcombe forced Kate off the road. What he doesn't know how to prove is how Ashcombe somehow got Dolly to the beach to find Kate's body. Sharona warns that Ashcombe could get Monk in serious trouble and tells him to talk to Dolly himself because she's having her private reading with the psychic later that day.
That afternoon, Dolly examines Sharona's skull to determine her future. Monk sneaks out of the waiting room and looks around Dolly's kitchen, but he knocks over a glass and comes to investigate. While Sharona tries to distract Dolly without success, Monk finds several varieties of sleeping pills in Dolly's cabinet. The psychic comes in and Monk says that he was looking for a glass of water. However, he can't bring himself to drink from the dirty glass that Dolly gets him.
Dolly has Monk come out to join them and does a Tarot reading for Sharona. The psychic tells Sharona that she soon will meet a romantic interest whose name starts with "D" and has a British accent. Monk keeps interrupting to ask if Dolly knew Kate, and the psychic insists that she didn't. When Monk asks how she found the body, Dolly explains that she has a sleeping disorder and take sleeping pills. When she finally dozed off, she woke up several hours later in her car, on the beach next to Kate's car. Sharona finally licks Monk's hand to get rid of him. He runs out to the car to get some wipes but then notices a small grey pebble on the parking lot and picks it up.
That night, Sharona drives Monk to Ashcombe's house. While she waits in the car with Benjy because she can't afford a babysitter, Monk picks out a small grey pebble out of the tread of Ashcombe's SUV and puts it in a plastic bag, smiling.
The next day, Monk and Sharona go to a hardware store and talk with the owner. He confirms that the two pebbles are made by the same gravel company in Mexico, and only a very few customers in the San Francisco area have had it installed. Monk figures that Ashcombe and Dolly met and are in on Kate's death together. He then gets on the loudspeaker and asks everyone to search for another pebble. No one bothers to help and Monk realizes that a clerk is sweeping up the floor. When the clerk admits that he dumped the trash in the dumpster, Monk sends Sharona to the dumpster to search for it. As she digs through the garbage, Monk finds the pebble in his hair.
When Ashcombe leaves the animal shelter, he finds Monk and Sharona waiting outside. He explains that he brought Kate's dog there because he never liked it, and Monk asks if Kate was insured. Ashcombe admits that Kate had a $2 million life insurance policy and Monk shows him the pebbles. When he asks Ashcombe if he has an explanation, Ashcombe defiantly says that he doesn't and asks Monk if he does. Monk doesn't answer and admits that he's in Ashcombe's way.
Dolly is at a studio filming the first episode of her new psychic show when Monk and Sharona pay her a visit. He warns Dolly that if she helped Ashcombe kill Kate then she's an accessory to murder. Dolly finally breaks down and talks to Monk privately, and says that… she's a fraud. She admits that she's never had a real psychic experience until now, but that finding Kate's corpse has convinced her that she really is psychic. Despite himself, Monk is convinced that she didn't work with Ashcombe to kill Kate.
That night, Ashcombe calls Jennie. She denies talking to the police and Ashcombe warns her not to lie to him.
The next day, Monk and Sharona go back to the crash site. Stottlemeyer talks to Benjy and learns that they're there. When he shows up, he asks Monk if he accused Ashcombe of murdering Kate. Monk is more interested in the fact that Stottlemeyer had to walk down to the beach because he couldn't find the service road to drive down. The detective tells Stottlemeyer that they couldn't find the service road either, and that it would have been impossible for Dolly to find it at night and locate the crash site. Stottlemeyer warns Monk that if he angers Ashcombe then he'll lose any chance of getting reinstated on the force. Despite that Monk tells his friend that if the body was never found then Ashcombe could never get the insurance. Ashcombe had to make sure that someone found the body, and Monk needs Stottlemeyer's help to prove Ashcombe did it.
A few hours later, Ashcombe returns home and is surprised to find the police there with Monk, Sharona, and Dolly. Dolly is reading the auras of the spirits and Stottlemeyer tells Ashcombe that Jennie has turned up missing. The psychic has traced Jennie's aura to Ashcombe's house.
Dolly has everyone join hands and Monk reluctantly does so using his elbows. She says that she can sense Jennie's pain and leads everyone to the living room. Sharona finds a bloody woman's sandal on the floor, and Stottlemeyer tells Ashcombe that Jennie's sister reported that Jennie was wearing similar sandals when she disappeared. Dolly then finds a poker by the fireplace, with traces of blood and hair, and takes everyone out into the backyard.
Jennie is lying in a shallow grave and Dolly, reading the dead woman's aura, says that Jennie tried to break off the affair with Ashcombe and he killed her. The psychic also says that Ashcombe forced Jennie to abort his child several months ago. Ashcombe insists that none of it is true and Dolly is a fraud. Monk reminds him that it is Dolly's authentic psychic abilities are what led them to Kate's body. Desperate, Ashcombe blurts out that he drove Dolly to the beach to find Kate's body. Jennie gets up from the grave and wipes off the makeup from her face.
Monk, smiling, explains that Jennie was glad to help them once they realized that Ashcombe had killed his wife. Ashcombe had access to Dolly's police record and knew that she used sleeping pills. He came to her house and chloroformed her, then got her into the back seat of her car and drove away after adjusting the front seat. He wore a wig and deliberately went through a red delight so the police would have the photo showing that "Dolly" drove to the beach.
Later, Monk and Sharona go for a walk. A beach runs up to Sharona and the owner, Daniel, comes over to get it. He apologizes and Sharona realizes that he has a British accent, and that he's the man Dolly saw her meeting. As they walk along, Daniel wonders if Sharona and Monk are an item and Sharona bursts into laughter while Monk insists it isn't that funny.