Action fan and prank king Max has a tough time. He attends the most boring school in the world, has trouble following all the rules and, on top of everything else, has the nerdy Frieda as a seatmate. His vibrant, bubbly nature is a thorn in the headmaster’s side – he wants to ensure law and order and numerous bans. It is exactly at the right moment that the inspector of the Boredom Control Authority shows up and an exciting and unforgettable class trip begins!

Max can hardly believe his luck: In a retirement home, he has finally found a gang that will let him join! Admittedly, it's the oldest and most wrinkly gang in the world - but that doesn't matter. He's found the best friends a 10-year-old could wish for in the elderly Vera, Horst and Kilian. Especially when, like Max, you're bullied in your new class and need help. But the gang's attempt to improve his school situation backfires. Horst, a former Bundesliga soccer coach, challenges Max's over-ambitious gym teacher Stöhle to a soccer duel: the school team including Laura and Ole against a selection of old geezers plus Max! And then the castle is haunted and a new case begins...