The ghoulfriends' new GFF, Wydowna Spider, starts to clear the cobwebs about the mysterious threat to Monster High. The previous generation of monsters formed a secret society that seems bent on turning the school into something that's more like a prison! But when Rochelle Goyle, Robecca Steam, and Venus McFlytrap uncover a second ancient group of monsters...the fate of the student disembody is in their hands!