Het Verraad van de Zwarte Roofridder plot
Johan, Hilde, Alwin and Robert are walking through the woods. Suddenly they see a man being beaten up by some knights. They come to the aid of the man and chase the knights away. The man, named Casper, introduces himself and says that knight Koen has sent him. He has a message for knight Bruno. The four take Casper to Bruno's castle where he tells his message to knight Bruno; the green seal is gone. It has been stolen and they suspect the black knight. Johan and Alwin set out together to get the seal back. But is Casper telling the truth? And was he sent by knight Koen?