A mysterious man found dead, clutching an old picture, a serial killer on the loose, and new faces to deal with — just another day for Monk and his assistant Natalie. As Monk digs into the multiple murders committed around the neighborhood and ties them to an odd commonality — an old couch — and Natalie digs deeper into the mystery man's past, secrets of all kinds will come to light, and some of them will be killer...
This book includes examples of the following tropes:
- Accidental Murder: The first victim of the story, Garson Dach, turns out to have been killed when the paperboy accidentally hit him on the head with a heavy Sunday edition. Unfortunately for him, he then panicked and tried to conceal it by taking the newspaper, making the legal consequences worse.
- All Girls Want Bad Boys: Natalie is disturbed to think that a number of the men she's been attracted to have killed someone. She mentions a lot of women's attraction to Dracula as an example of the general idea, and promises herself that she'll assume any man attractive to her is a murderer until proven otherwise.
- Alliterative Name: A guy involved in the primary case is called Rico Ramirez.
- "Be Quiet!" Nudge: Stottlemeyer nudges Lt. Devlin and tells her to shut up after she makes a comment about the cleanness of the streets that could easily throw Monk into a total panic.
- Broken Pedestal: Monk becomes depressed when he realizes that Jerry Yermo and the crime scene cleaners, who he loved because of their intense thoroughness and the feeling of belonging they gave him, shot Stuart Hewson.
- Character Name Alias: Yuki notices that the dead man in the hotel seems to have renamed himself after the title character in the 1933 version of The Invisible Man.
- Chekhov's Gun:
- Natalie is surprised when Jerry Yermo picks her up in a Porsche, which would seem out of range for a crime scene cleaner. It turns out he's in deep debt due to uncontrolled spending.
- Jerry tells Natalie that he got into his current job for the money. That's also what led him to steal the diamonds.
- Chekhov's Gunman: The crime scene cleaners that Monk spends time with turn out to be responsible for shooting a rail engineer who caught them stealing from someone's house.
- Lying to the Perp: Lt. Devlin sets up a fake murder scene using William Tong's car, making it look as though Rico Ramirez caught up to him and killed him over the diamonds. Corinne holds out quite a while, but under the knowledge that she can't expect police protection if she can't give them a reason she thinks she might be in danger, she cracks and confesses to the theft and ultimately the murder.
- Mugging the Monster: A double variant: an ex-con named Rico Ramirez had stolen some diamonds and before he was caught, he stashed them in a couch belonging to his girlfriend Cheryl Strauss. She sold it to a thrift shop owned by a man named Casey Grover, who in turn sold the couch to a realtor named Mark Costa. While Ramirez did five years in jail, Costa found the diamonds and stashed them in the walls of his house. When Ramirez gets out, he tracks down his diamonds, first killing the thrift shop manager, then using his computer to track down Costa. After killing Costa, he ransacks Costa's house looking for the diamonds, but when he can't find them, he tortures and kills Cheryl Strauss instead. But then someone else finds the diamonds: a crew of four cash-strapped crime scene cleaners named Jerry Yermo, Corinne Witt, William Tong and Gene Tiflin. They discover the diamonds by ripping open the walls in Costa's bedroom. However, they are witnessed by a BART train engineer named Stuart Hewson, who was watching them through a telescope at his house a few blocks away. Hewson tries to blackmail Jerry Yermo. In response, the crew go to his house and shoot him.
- O.O.C. Is Serious Business: Monk being willing to abandon her bathroom, half-cleaned, shows Natalie how impressive his breakthrough must be.
- She Cleans Up Nicely: Natalie is shocked by how gorgeous Lt. Devlin looks in a mini-dress, though part of the surprising change is her attitude — tough, no-nonsense cop won't work for the plan she has in mind.
- Shipper on Deck: Monk tries to convince Natalie to go for Jerry Yermo, the biohazard cleaner he meets in the beginning, and even sets them up on a date. Unfortunately, it goes out the window when he turns out to be the killer.
- Shown Their Work: Goldberg created Natalie's subplot with a lot of background information about housing architectural styles and research about binoculars and optical lenses.
- Weight Woe: Monk points out during the first investigation that Natalie has gained 2 pounds and 4.8 ounces and then tells Stottlemeyer that he's gained even more than she has. Natalie blames her sweet binging now that her daughter is at college, and Stottlemeyer attributes it to the great home meals his wife cooks.
- Working the Same Case: When a BART engineer named Stuart Hewson is shot and killed in his Noe Valley house, Monk deduces that it is related to three knifings in the area committed by ex-con Rico Ramirez because Hewson's house had a view into the bedroom of Mark Costa, Ramirez's second victim. However, from the spotlessness of the crime scene and the number of bullets put in the body, Monk deduces that the killers are actually Jerry Yermo, William Tong, Gene Tiflin and Corinne Witt, four crime scene cleaners he has been hanging around the past week. Hewson had spotted the crime scene cleaners discovering the ex-con's fortune of diamonds in Costa's house. They killed him because he was trying to blackmail them.