In Chinatown, Karl Torini is performing sleight of hand at a restaurant for a Thai drug lord, as the latter's bodyguards watch. When Torini makes the drug lord's his watch disappear and he demands it back at gunpoint. Torini then agrees to handle a drug shipment of heroin from Thailand to San Francisco.
At the Magic Castle in San Francisco, The Great Torini is rehearsing his act when CPA and amateur magician Kevin Dorfman comes to him with something private. He informs Torini that the airline receipts show that his equipment weighed more on the way back then the way there, and that it's happened several times in the past. Kevin thinks the airplanes are ripping Torini off. Torini tells Kevin to forget about it and then asks him to fill in it while he takes his assistant Tanya to Reno to get married. Kevin isn't sure but Torini assures him that he can do it.
Kevin recruits Monk and Natalie to watch his act as he performs (badly). Monk wonders how he got the job and Kevin talks about the extra-heavy equipment. He then calls Monk up to perform his Vanishing Cabinet illusion. Monk reluctantly gets up but refuses to get in the box.
At the Magic Castle on the night of his performance, Kevin is preparing to go on stage when Torini calls on speakerphone to inform everyone that he and Tanya are getting married. Kevin promises to dedicate his show to the happy couple. He goes on stage and performs, and it doesn't go well. Natalie and Monk watch from the somewhat hostile audience. As they start to leave, Kevin pulls off his vanishing rabbit trick, sort of, and ends his show. While Natalie and Monk wait for him, Kevin reviews his performance in his dressing room, and then turns as a familiar person enters his room. Monk finally goes backstage, waving to a maintenance man, then finds Kevin and discovers him lying dead on the floor.
Stottlemeyer and Disher arrive to investigate and Monk and Natalie admit they have no idea why Kevin might have been murdered. Monk is overwhelmed with anguish but insists on investigating the murder. Kevin was strangled to death with something thin and strong. They haven't found the murder weapon yet. Monk finds black paint on Kevin's neck, the black paint that magicians paint their levitating wire with, and realizes the killer was a magician. When the stage manager says that maintenance doesn't work that day, Monk realizes the maintenance man he saw was the killer.
At Kevin's funeral, Natalie and Monk meet Torini and Tanya, and Monk recognizes a gesture that Torini makes as the same that the maintenance man made at the club. Monk introduces himself and notices that Tanya doesn't have an engagement ring. Monk is sure Torini is the killer but Stottlemeyer points out that they traced Torini's call and it was made from a hotel in Reno. He promises to help if he can, but Monk doesn't know what to tell him.
Monk and Natalie go to see Tanya, who shows them the ring that Torini bought them the previous night. They see Torini's rabbits and Natalie gets the impression Tanya knows more than she's saying. As Monk examines a magic cabinet, Torini makes his entrance and talks about misdirection. Monk notes that he saw Torini, dressed as a maintenance man, but Torini denies it. He claims he chose Kevin because he was so talented but Monk notes that Kevin was horrible. Monk is sure Torini did it, but the magician points out he doesn't have a motive. Torini writes out a confession but makes it disappear in a flash of fire.
Later, Monk and Natalie pack away Kevin's belongings and Monk admits that Kevin drove him insane because he wouldn't shut up. Natalie's phone rings and she discovers that she put it on a cabinet with a disappearing trap door. Monk examines the box and realizes that there are secret compartments, and Torini must have been smuggling something to account for the extra weight.
Torini is performing on stage that night and Monk and Natalie are in the audience. He presents the Zig-Zag illusion and calls Monk up on stage to help him. Monk is reluctant but Natalie encourages him, saying he has to do it for Kevin and slips him something. Torini eventually goads the claustrophobic Monk into entering the cabinet. As Torini performs, Monk runs a test in the cabinet and then opens the front to reveal that the cabinet tested positive for heroin. As Monk starts to explain what happened, Torini closes the cabinet panel and then whispers to Tanya, who reluctantly goes off stage. The magician opens the cabinet to reveal that Monk has disappeared.
Stottlemeyer, Disher, and Natalie confront Torini afterward but he claims he has no idea where Monk went. Downstairs, Tanya visits Monk, who they have handcuffed and tied to a chair. She explains Torini is going to kill Monk and dispose of the body in the furnace. Upstairs, Torini says he has to leave while below, Tanya apologizes for her involvement but refuse to let Monk go. The phone rings but Tanya doesn't answer it, noting it's an extension. Monk finds pipe tobacco and explains how Torini did it: Tanya and Torini went to Reno, he made sure he was seen, then returned to the club. He hid in the basement and had Tanya call the theater. Torini picked up the extension and made the announcement on the speakerphone, and the two of them staged a conversation as if they were together.
Torini arrives and prepares to kill Monk using a magic cord. Above, Stottlemeyer finds the trap door in the stage. Monk tries to hold Torini off and Tanya reluctant helps the magician and takes the rope from Torini. As the magician holds Monk's legs, Tanya tries to slip Monk the key to the handcuffs by kissing him. Monk spits it out and Torini realizes that Tanya is betraying him. Before Torini can dispose of her, Stottlemeyer and Disher arrive and arrest him.
Later, Natalie and Monk watch Kevin's video will and testament, and talks… and talks… and talks. Monk smiles affectionately and lets the recording run.