Mrs. Bell challenges her science students to invent their own robots but when they start malfunctioning it becomes up to the DATA Set to deprogram the machines before an army of robots take over the school.

Asked by a Bollywood star for help protecting a valuable ruby, Geronimo Stilton and Hercule Poirat are inadvertently cast in the actress's film in spite of limited acting skills and are horrified when an anonymous thief makes off with the ruby.

Eleven-year-old Demon had never met his father, the god Pan, until the day he was whisked away to the stables of Olympus and charged with looking after all of the mythical creatures there, a task which is complicated by the tempestuous gods and goddesses and Heracles, who keeps killing the immortal beasts.