Diederik the Jester and his sister Marie hope to find work in the castle of the newlywed Countess Isabella. Unfortunately, he quickly falls into disrepute.

Marie wants to become a guard, but Rolant blocks her. Meanwhile, Diederik tries to win over Ferguut's flashy friends.

Count Baldewijn arrives, acting on behalf of the king, to grill Isabella. Meanwhile, it becomes clear that Marie and Diederik have a dark past with the count.

The castle is in turmoil when Diederik brings a Viking. Moreover, Marie is injured, making it impossible for her to avoid Isolde.

Ferguut wants to go hunting with Diederik, but Diederik hates adventure. Meanwhile, Isabella tries in vain to unburden herself to Ageeth.

The arrival of a well-known traveling artist stirs something in Diederik. He wants to be more than a silly jester. Meanwhile, Ageeth is on the trail of a witch.

Count Baldewijn and his army are on their way to the castle. While everyone prepares for the siege, Marie departs on a secret mission.

Baldewijn seems to have the upper hand. Ferguut is the only hope for salvation, so things look bleak for the castle and its inhabitants.