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...