The End of Orson Eerie?

Eerie Elementary is planning a big Halloween-type celebration for Eerie Day, including hosting a "haunted house" at the school itself; but the spirit of the evil scientist Orson Eerie sees this as the chance to finally triumph over the intrepid hall moniters, Sam, Lucy, and Antonio--and it is up to them to prevent a catastrophe and perhaps even defeat Orson and banish him from the school forever.