The book opens with Amazing Maurice (a sentient cat), a group of talking rats (the Clan), and the human boy Keith travelling in a mail coach to a small town called Bad Blintz. The group plans to enact a scheme they have used many times before, where in the rats pretend to infest the town and Keith poses as a rat piper to lead the "vermin" away for a small sum of cash. Although Maurice sees nothing wrong with this hustling business, the rats find it immoral, and convince Maurice that this town will be the last one they rob. Upon arriving in town, the group discovers that the people are convinced of a massive rat infestation, and have spent much of their savings on two rat catchers. Despite their efforts, food continues to disappear from the town. As the rats move into the town's underground, they discover an overwhelmingly large number of rat traps, but no live "keekees" (rats who can't talk or think). Aboveground, Maurice makes similar observations, including that many of the rat tails the rat catchers display as proof of their successful hunting are in fact shoelaces. Maurice and Keith meet the mayor's daughter Malicia and introduce her to the talking rats.