De Club van Sinterklaas: Geheimen van de Sint S01 E04 Episode 4

The girls from KADO find Sinterklaas' magical diary, which contains all kinds of secrets of both Saint Nicholas and all the Petes in the castle. It also contains a route to Sinterklaas' secret room with magical objects. When the Piets discover that their secrets are in this diary, they secretly tear out pages. And that causes big problems.