The Baron, B2 and Vlugge Japie have been in prison since the previous adventure. Now that they have escaped, they want to take revenge on Bassie and Adriaan. They steal a valuable crown from a museum after escaping from prison. They hide in a secret room of an abandoned castle. The crooks want a large amount of ransom for the crown, otherwise they will have it melted down, and they then lure Bassie and Adriaan into a trap. However, the duo escapes. But then it turns out that the baron accuses th...