The Trap Door Sezon 1 Odcinek 8: Ghoulies

Berk and Boni are going through things in a room that's been left untouched for a long time. Berk finds an old book of spells and reads one out, summoning up the 'Ghostly Ghoulies' ... They rush back to the kitchen to find the trap door thumping open and shut and ghoulies floating about the place. To make them go away he has to read the spell backwards...