Humphrey Bogart's got nothing on this rat! Inspector Octavius O'Malley is on the case. It started with some missing cobblestones and a bump on the head of one of Rodent City's young police rats. And it is not the mice who are to blame ... Even though Ocko makes a mess and loses his job, Rodent City's finest detective (self-confessed) can't be kept from pursuing the case. A rat has to pay the rent, so Ocko hangs out his shingle as a private investigator. His first client wants him to find her missing son, whose workplace has special significance for our doughnut-lovin' hero. And could it be that there's a link between the two mysteries?! When Ocko's informant -- a down-and-out moggy named Mulligan -- puts him on the unsavoury scent of a creepy cat cult, things get dicey indeed for Ocko, Spencer and Patrick. And the villain of the piece might not look familiar at first glance, but a rat with a brilliant, diamond-hard mind like Octavius O'Malley's knows that appearances can be deceiving ...