The bosom friends Stef and Victor live in the South Limburg mining village of Oranjedorp, where everything revolves around the Oranje Nassau coal mine. Stef and Victor share joys and sorrows, but above all their fascination for the coal mine that borders the village. In their secret club, Stef and Victor come up with all kinds of daring plans to get into the coal mine. A girl, Wietske, finds out, but can she be trusted? And the more the boys discover about the coal mine, the more doubt sets in over their plans. Especially when the mine shows its most dangerous side.