After oversleeping yet again, Alfons manages to catch the bus to his class trip to the Baltic Sea at the last minute. In his luggage: lots of adventure, funny pranks and - wait a minute - his mother's clothes?

To this very day, kids believe that the stories of "The Wild Soccer Bunch" are the best in the world, and that's why Leo, Elias, Finn, Joshua, Oskar and Matze, replay their heroes’ legendary games every spare minute. One day a darkly dressed young man hands them a mysterious map that leads the boys into unknown territory.

En route to a party they are not keen on attending, the Famous Five are almost relieved when Aunt Fanny's car breaks down, stranding them in a small town. To pass the time, they visit the local natural history museum, where some newly-discovered dinosaur bones are being unveiled. Here they meet Marty, who tells them that his father, long dead, supposedly found a complete dinosaur skeleton and made a map of its whereabouts. Unfortunately the map has been stolen. Unable to let a good mystery go unsolved, George, Julian, Dick, Anne and Timmy, join a guided hike through the Valley of Dinosaurs. But their fact-finding mission soon turns into a race to find the dinosaur when they suspect that the thief is one of the group.

Clumsy peculiar pupil Alfons Zitterbacke dreams of being an astronaut and wreaks havoc anywhere he goes but against all odds wants to proof everyone who is teasing him wrong especially his father who wants him to be more of a 'normal' kid.