Following this, her teenage daughter Julie "hires" him to investigate the death of Sparky, a popular firehouse guard dog who was struck with an ax on the same night that a house inferno was occupying its owners.

Adrian Monk, an obsessive-compulsive private detective, moves in with his assistant Natalie Teeger while his apartment is being fumigated.

Julie tells Natalie that Sparky, a firehouse dalmatian who visited her school during Fire Safety Week, was found murdered the previous night.

However, Monk observes that from Stoval's position on the couch, her view of the TV was blocked by an empty chair, indicating she had a visitor.

Joe says that the only person he can think of who disliked Sparky is Gregorio Dumas, a dog breeder who lives across the street from the firehouse.

Dumas threatened the fire company with a lawsuit after Sparky impregnated his prize show poodle Letitia.

Dumas says he was at home on Friday night, watching the firehouse to make sure Sparky did not enter his property.

By burning down the house, the killer destroyed all forensic evidence, including usable fingerprints and DNA.

She was also the lone holdout against a development plan by Lucas Breen, a local real estate tycoon, to demolish the houses on Stoval's side of the street and build an upscale condominium block.

When Monk asks for an alibi, Breen claims he was at a fundraiser at the Excelsior Tower Hotel downtown with his wife.

He used Letitia to distract Sparky so he would not bark, while Dumas searched the basement, which historical records show is where a famous 19th-century train robber stashed his treasure.

The only plausible explanation for Breen posing as a fireman is that he realized he had left incriminating evidence in Stoval's house.

Randy Disher calls Natalie to tell them that the mugger has confirmed that Breen was wearing his overcoat when he was mugged.

Joe and several off-duty firefighters pitch in to help root through the recently collected trash at the city dump, but without finding the overcoat.

While Monk is preparing to move back home, he tells Stottlemeyer to arrest Mrs. Throphamner, Natalie's elderly next-door neighbor who has been babysitting Julie.

He says that she murdered her husband; she has been wearing his dentures in place of her own, and constantly planting and re-planting roses to conceal his decaying corpse buried in her garden.