Officer Adam Kirk, an old friend of Stottlemeyer's, steps off a ferris wheel to find the young man he was riding with, dead from a knife in his chest. He is then arrested for murder. Stottlemeyer enlists Monk's help to investigate the case unofficially, even though Monk believes the hair-triggered cop is guilty. Monk then discovers that the bruises on the victim's body were self-inflicted.