At the fair, Uncle Fax once again raves about the good old days. He also has a nice souvenir photo taken in an old barrel, just like back then. But suddenly the barrel starts rolling. "Free Willy" à la Fix and Foxi. Together with Lupo and Lupinchen, they want to help a baby whale that has got lost. On the way back to the sea, the whale goes into the net of a circus director. Of course, the friends immediately start a liberation campaign. Fix and Foxi, Lupo and Lupinchen accompany Professor Knox on a cave expedition. They actually find frozen mammoths. While Professor Knox goes to get his colleagues, the children prepare a welcome party and Lupo unfortunately thaws the mammoths. And they are suddenly alive. Pip and Pep are allowed to bring their mascot, a nasty iguana, from school. At home, this iguana manages to escape, causing hysteria in the family.