On December 8, several Zwarte Pieten appeared at the bedroom window of Tommy and tapped until he woke up. They warned Tommy that they knew what he did and their master was coming for him. Tommy's father Wally saw them, too, and called the Ghostbusters for help. The next day, Egon Spengler, Peter Venkman, and Special Agent Melanie Ortiz investigated. Ortiz gathered blue slime left by the Pieten for Egon. Egon decided to check Tommy's bedroom one more time before they moved on. He encountered the Sinterklaas Ghost and his Zwarte Pieten. The ghost was angered and left the house. Egon meanwhile was attacked by the Zwarte Pieten. One even stole his glasses. Since the controlling entity turned out to be a ghost of a deceased human, the Pieten were deemed to be only manifestations  and appeared to have dissipated once the ghost was trapped.