Actually, the four friends of TKKG just wanted to go for a bike ride, turn their backs on the city of millions and spend a relaxing weekend in the countryside.

But when they are surprised by a thunderstorm and have to seek shelter in an abandoned hotel, they come across a terrible secret ... And before they know it, they are in the middle of a thrilling criminal case, in which it quickly becomes clear that this is no ordinary case. The clues lead into the past - a past that scares the inhabitants of the small village Oberfeldbach so much that they don't want to talk about it.

Is this case perhaps a bit too big for TKKG?