Kwiatkowski is a real detective who loves milk and 'Carpenter's' chewing gum. Instead of homework he has night ambushes, instead of children's entertainment he gets into the dangerous adventures. The most intricate crimes are doomed to failure if he gets involved. The school janitor Comisarek sees ghosts during the night shift. Kwiatkowski considers such mysticism to be adult fears, but agrees to investigate the case. The detective will have to fight with the unknown and find out what secret the pink ghost hides.