Captain Leland Stottlemeyer relies on Adrian Monk to solve his most baffling cases, but when the captain is faced with budget cuts, Monk's fees are one of the expenses he trims. Monk is too compulsive to stop investigating; he resorts to calling in tips under assumed names, infuriating the captain.
But when Stottlemeyer is arrested for murder, he turns to the only detective who can prove his innocence. That is, if Monk can overcome some potentially crippling obstacles along the way?

Ever since an unsolved train robbery in 1962 made it famous, people have made their way to the town of Trouble in California's gold country to search for the booty that train robbers supposedly dumped in the botched heist. When Trouble's museum watchman is murdered, Monk and his assitant are sent to investigate.