After ten years of traveling the seven seas, Floris van Rozenmond returns home with his Indian friend Sindala. He find his castle occupied by Maarten van Rossum and soldiers from Gelre who are using it to collect toll and taxes. Van Rossum's enemy, Wolter van Oldensteijn breaks into the castle to release a prisoner and Floris & Sindala join him in the fight against Gelre. Sindala decides to remain with Floris in the low countries to help him get his castle back.
Van Rossum is expecting the biggest cannon ever constructed in order to wreck Van Oldenstein's defenses in one fell blow. It is up to Floris and Sindala to try and sabotage the cannon before it gets there.
A cart full of valuable weapons is ambushed by men from Gelre. Van Oldensteijn is convinced there is a traitor amongst his men. Sindala devices several ways to trap the culprit. When the traitor manages to step one step ahead of them at each turn, Sindala decides to catch the man by using his cunning against him.
Gwijde van Suikerbuijk from Gent comes to Oldensteijn to warn against an imminent attack by Van Rossum. Wolter, Floris and their men immediately set out, leaving Sindala and Gwijde to defend the castle. Unbeknowst to them, the infamous Lange Pier, King of Friesland is planning to rob the treasury of Oldensteijn.
Filips de Schone has commissioned a painting from Jeroen Bosch. The sergeant of Gelre asks Lange Pier to ambush Bosh on his way to the duke and steal the painting. Luckily, Bosh runs into Floris & Sindala who decide to help him along his way.
Floris and Sindala are carrying an important letter that needs to be signed by their commanding officer Reinbout. On arriving at his castle, they find it empty save for Reinbout's jester. Posing as three jesters, the trio sets out to rescue Reinbout from the dungeon of Van Rossum.
Barend van Hackfort infiltrates Oldensteijn's kitchen and puts a sleeping potion in the soup for Wolter's birthday. Floris and Sindala are the only two left awake and Sindala deduces the cure can only be prepared by using mandrake juice.
Van Rossum is after the last will and testament of Gravin Ada van Couwenberg's uncle. Together with her lady in waiting Viola, Ada dresses up as men to bring the will to court. Unfortunately they walk right into the clutches of Lange Pier and his men.
Roland and Govert are both vying for Isabella's hand in marriage. Her father vows that the man who can cure her mysterious illness can claim her as his bride. When they learn that a goblet with healing powers is to be the main prize at a tournament held by Wolter van Oldensteijn, both Roland and Govert disguise themselves as Bourgondiers in order to enter.
Floris has allowed Roland to win the healing goblet so he may find out why a man from Gelre has entered the tournament. However, Roland is immediately ambushed and robbed of his prize by his rival Govert. Floris and Sindala decide to help Roland win the hand of his beloved Isabella.