Taxes are hard on poor the farming community, especially the Kremer family, who have a sickly young girl. Kremer's brother Lei tells stories about the legendary Bokkenrijders, inspiring his young nephew Martien to take action.
Gold taxes have been stolen from the safe inside the church and the pastor is arrested for being an accomplice. The mysterious Zwarte Kapitein returns to form a new group of Bokkenrijders.
De Bokkerijders search Kremers farm looking for the stolen gold. Their leader, Zwarte Kapitein, vows to save the old pastor from the gallows. Martien and Wolf visit a gypsy camp and get their fortune told.
Martien and Wolf manage to find Lei in his hiding place but there is no sign of the stolen gold. Zwarte Kapitein manages to save the pastor's neck in broad daylight and brings him to Dr. Kirchoffs to mend his wounds.
The Zwarte Kapitein tells Martien that the Bokkerijders will attack Kremers' farm at night. Lei tricks Kanunnik into allowing the gypsies to stay on his land. The Schout searches for a traitor to help him unmask the Zwarte Kapitein.
The Bokkenrijders attack Kremers' farm, but Martien has made preparations to defend the house. The Zwarte Kapitein finds Lei's hiding place and the stolen gold, but is betrayed by one of his men, van Brakel.
It's the first day of working in the mines for the men in the Kremer family. The Schout suspects Dr. Kirchoffs of being the Zwarte Kapitein, so he orders the doctor to attend the sentencing of the three captured Bokkerijders.
Both Dr. Kirchoffs and the Zwarte Kapitein appear before the hanging of the three captured Bokkerijders. All three of them escape, including the traitorous van Brakel, who heads straight for Lei's hiding place.
Martien gets more responsibility at the mines when he is made teller. He discovers that the mines are dangerously close to collapsing. The Pastor is visited in his hiding place by his old friend Henry le Groit.
Henry le Groit is organizing a revolt at the mines. When Dr. Kirchhoffs is called when Lotteke's illness takes a turn for the worse, Martien makes an important discovery.
Martien has to go into hiding because he knows the Zwarte Kapitein's true identity. But when his father and brother are held hostage by the Scout, he decides to give himself up.
