When a sarcastic and unpopular ringmaster is murdered by an acrobat wearing a face mask and a Ninja-like costume, Stottlemeyer suspects an animal trainer who not only has a motive but also owns the murder weapon. Monk, however, suspects the ringmaster's ex-wife, a trapeze artist billed as The Queen of the Sky who is also a sharpshooter. Meanwhile, the Monk alienates Sharona by telling her that her fear of elephants is irrational and advising her to suck it up.

Monk suspects that the man responsible for the mail bombing murder of rich and beautiful Amanda Babbage is the victim's brother, Brian – who has been in a coma for four months after attempting to lure Stottlemeyer and Disher into a car chase and crashing into two cars. Since the package was postmarked three days before the bombing, Stottlemeyer is naturally skeptical, but he prefers siding with Monk to tagging along behind Agent Grooms of the Bureau of Alcohol, Tobacco, and Firearms, who suspects the victim's other brother, Ricky.

When Monk's paperboy is murdered on his doorstep by a guy looking to steal his newspapers, Monk turns to the pages of the newspaper for clues to solve the baffling crime.

On her way to film a documentary (apparently about a union dispute), Captain Stottlemeyer's wife, Karen, is badly injured when her car is struck by a tow truck whose nonunion driver has been killed by a sniper. Distraught and furious, the captain blames a sleazy union official and his thug, a theory that seems to be confirmed when a second tow truck driver is murdered. But Lieutenant Disher, in charge of the crime scene investigation, discovers an odd detail that doesn't fit well with this scenario – both the assailant and the murdered truck driver were barefoot. Empathizing with the captain's anguish, Monk offers to do whatever he can to help and of course ends up investigating the case. A small dog that follows Sharona from the crime scene leads her to the home of a handsome man who seems attracted to her, but Monk is more interested in the next-door neighbor's off-kilter sundial. Meanwhile, the captain, fearing that his wife will die, becomes increasingly violent, taking out his anger...

Who would murder a death-row inmate forty-five minutes before his execution--and why? That's the question Captain Stottlemeyer asks Monk--but Monk's response is to ask why it matters. As Monk is hurrying to leave the prison, however, he gets a phone call from his old nemesis, Dale ""the Whale"" Biederbeck, that changes his plans. The police consider Dale a suspect in the inmate's murder (the young man owed him twelve hundred dollars) and refuse to give him a window in his cell until his name is cleared, so Dale strikes a bargain with Monk--solve the case and he'll provide information about Trudy's murder. After interviewing the cook who prepared the dead inmate's last meal, Monk notices that another cook never clocked out the evening before. The missing cook is found dead in a freezer with a wad of bills in his apron pocket--clearly the person who bribed him to poison the inmate was afraid he would talk and killed him, too. On his way out of the prison, he receives another phone call, th

In yet another case of murder in a room locked from the inside, a music producer is found dead with bullets in his back, head. and chest, clearly neither an accident nor a suicide. But this time there's a further twist: the dead man's pet chimpanzee, Darwin, is caught with the murder weapon in his hand. Not wanting to make a monkey of himself by falsely accusing a chimpanzee of murder, Stottlemeyer takes the chimp into the interrogation room, tempting the animal to fire what he thinks is an empty gun. Meanwhile, Disher realizes that he's inadvertently given the captain a loaded gun and panic ensues. When the gun goes off, endangering not only Stottlemeyer but Disher, Monk, and Sharona as well, Stottlemeyer is persuaded that the chimp is guilty and is ready to allow animal control to put him to sleep. Sharona, however, is convinced that Darwin is innocent. In desperation, Sharona resorts to breaking and entering to rescue Darwin, persuading the most unlikely person imaginable to take hi

After witnessing a Chinese gangland murder, Monk has to stay in an FBI safe house--a cabin in the woods--in the protective custody of Agent Grooms, with Stottlemeyer and Natalie as company. Awakened by a man's scream, Monk convinces Stottlemeyer and Natalie that a woman in a nearby cabin has murdered her husband. Agent Grooms, however, remains skeptical. After Grooms disconnects their telephone, Stottlemeyer locks him in the bathroom and the three ""borrow"" Grooms's car and set out in a rainstorm to investigate, only to get stuck in the mud on the way. Meanwhile, Disher and his new girlfriend Hayley are encountering a strange circumstance--the fortunes in their fortune cookies keep coming true. When a fortune informs Disher that an old friend is in trouble and only he can save him, Disher immediately sets out to save Monk, unaware that he's leading a pair of hitmen to the FBI cabin. After a rainy night in the car, Stottlemeyer leads Natalie and Monk through the woods toward the neighbor

When Monk, Natalie, and Julie get stuck in a traffic jam after a multi-car collision blocks the freeway, Monk gets out of the car to investigate. He soon deduces from the absence of skid marks and other clues that the young man in the overturned Volkswagen that caused the pile-up was murdered and his body placed in the car to make his death look like an accident. But the highway patrolman in charge of the ""accident"" scene wants nothing to do with Monk (or the not-very-successful lawyer who has latched onto him), and the mountains blocking the signal prevent Monk from calling Captain Stottlemeyer for an authorization to investigate. Monk briefly returns to Natalie's car, where he finds Julie in need of a bathroom and Natalie nursing an injured wrist. Unfortunately for them, Monk's mind is on the fatality, and he returns to the Volkswagen. The angry officer gives him the victim's name and occupation (environmental activist), but he still refuses to listen to Monk's evidence. Meanwhile, t

Monk goes undercover as an office worker to solve a case.

When an officer dies after drinking poisoned wine sent to Captain Stottlemeyer as a Christmas gift, the captain suspects Frank Prager, who tried to shoot him outside a bar several months earlier. Searching the crime scene for clues, Monk notes that the bullet holes seem to form a pattern, but neither he nor Stottlemeyer can figure out the message they're intended to convey. After trying unsuccessfully to talk with Prager's young daughter, Monk goes under cover as Santa Claus. This time he learns that Prager is hiding in a church with ""three ladies"" in front of it. But when Prager is caught and interrogated, it's clear that he had nothing to do with the poisoned wine. With the other suspects on Disher's list also eliminated, Monk and the captain are back to square one. But when Monk opens the card accompanying his gift from the Christmas party, he finds the clue that solves the case.

Monk finds himself adrift in an ocean of filth when a garbage strike brings San Francisco to a halt...and Adrian to near-paralysis.

When Monk's truck driving father rolls into town at Christmastime, Monk joins him on the road, where they stumble across a very peculiar mystery.

Natalie suspects a theater critic is responsible for a murder, despite the fact that he was present to review her daughter Julie's play at the same time the victim died.