Every year, Sinterklaas and the Pieten eagerly look forward to their big journey to the Netherlands. In the castle, preparations are in full swing. The two new "Pieten-in-Training" (PIO's for short) are soaking up everything like sponges, eager to prove themselves. Everything seems to be going according to plan until disaster strikes. Jean-Claude takes a nasty tumble down the stairs and ends up bandaged. To make matters worse, his Aunt Poets suddenly shows up at the castle. She insists on taking over the housekeeping.