Join Geronimo Stilton as he embarks on a thrilling adventure to discover how to keep our cities – and the whole world clean! When his beautiful hometown, New Mouse City, was swamped with mountains of trash, Geronimo, along with his friend Hercule Poirrat, sets out on a mission to fight pollution. In this inspiring adventure, they learn that small actions, like keeping streets clean, reducing waste and recycling, can make the world a better place.