Plot

There seems to be little room in society for imaginative people. Paul's father was personally affected by this. When he told the people of his village how old records indicated there was a legendary cave inside the Ursulenberg mountain, they thought he was a crank. But more than a year ago, he left on an expedition and never returned. Did he find the cave and have an accident there? Paul has a hard time coping with his father's disappearance. He keeps thinking about what his father had told him: "We have to dream as much as we can. How can all the wonderful things that could change the world become real if no one dares to imagine them?" On the last day of school, Paul picks up his father's notes and decides to go in search of the cave with his best friend. Thus begins the summer of their lives.

German schoolboy Paul Haller is bullied since his dear, unconventional father Thomas disappeared, people doubting if the unpopular 'crank' really was on an expedition to find the legendary cave in Ursulenberg mountain. He strikes a friendship with corpulent, moody halfwit Max 'Fatboy'. Having studied and brought Thomas's notebook, Paul takes buddy Max along, escaping from the hike on the last school day, to prove and complete father's expedition. The perilous journey tests their unequal friendship and courage, while the mayor orders a search party which they carefully avoid. Reaching the cave is the start of a last, new set of challenges for all.—KGF Vissers