The planned marriage between Premierpiet and Probleempiet is in jeopardy, scholars Hans and Frans Steenstra have been kidnapped, and a rare ruby has been stolen from the Rijksmuseum. The dangerous Dr. Brein is behind all of this. Sinterklaas must intervene and even sends his Pieten on a trip to Switzerland to prevent Dr. Brein's criminal organization from gaining power.
Museum Directeur

Donnie Bianco
Boris
Sluwe Ruudje

Hans Steenstra
Tante Til

Pittige Pia
Patserpiet 1
Bisschop van Zwitserland

Principe Piet
Probleempiet
Marja, Assistent museumdirecteur

Joris

Verkoper
Padvinderpiet
Dr. Brein

Ambtenaar Burgerlijke Stand
Agent de Bok