Trudy's father, a game show producer, invites Monk to Hollywood to determine if the host is helping a contestant cheat. Monk has to become a contestant himself in order to clinch the case, as well as to confirm his suspicions about the death of the host's assistant.

Monk is having a hard time finding a new assistant, and Natalie might be just what he is looking for. But first he has to take her case and solve the mystery of the intruder who seems inordinately interested in her daughter's pet fish.