Sophie and her family are visiting the city Museum of Natural Sciences where Prof. Snork is working on a new time machine... Suddenly the whole machine starts to shake and, with a bright flash of light, a tiny mammoth named Woolly and a sea turtle by the name of Gertrude materialize next to Felix! All three of them are then catapulted into a journey through time in which they face prehistoric cavemen and even meet Queen Nefertiti in ancient Egypt. However, the return home will not be easy, as Sophie and Prof. Snork work on getting the machine back to the present. Meanwhile, Felix is hosted by the Vikings, meets a whale, comes to know the peoples of the Native Americas and goes adventuring on a Pacific island. Felix and Wolly even participate in a medieval tournament before returning to the safety of Sophie's arms.

Old Petterson lives on the edge of a small village somewhere in Sweden. Together with his cat Findus and his ten white hens he always experiences wonderfully funny and exciting adventures. The stories are about friendship, travel and the crazy and loving everyday life of Pettersson and Findus.