Geronimo Stilton’s newest adventure starts on the note of something strange occurring at the New Mouse City. According to the news, rodents were getting hiccups and weird green warts, and were falling ill because of stomach upsets all because of cheese. And, cheese is something which the whole community of mice cannot live without.

Hence, Geronimo Stilton along with his detective friend, Hercule Poirat, goes into the mission of solving the mystery of faulty cheese. Will they be successful at solving this mystery that could save the whole mice federation?