Everyone knows the story of the Pied Piper of Gammeln. The story is very simple - a magic pipe lures hordes of rodents into the water, and they drown. Meanwhile, everyone forgets that rats swim beautifully. The fairy tale came true in one of the cities of the Disc World. But it all started when the rats living in the basements of the Invisible University suddenly became smarter, learned to talk and formed a Clan. Then, these Educated Rats met the street cat Maurice, who turned out to be a cat that was unusual in every way. Firstly, he also knew how to talk (a consequence of living on the territory of the Invisible University), and secondly, he turned out to have amazing business acumen. Maurice found a boy who could play the pipe, and the fairy tale came to life. Amateur translation.