It's been 3 years since the defeat of Kai's evil vampire spirit. Since Kai was free from his spirit trapped in its mirror the ninja lived in peace forever, well, at least they hoped... When a trip in search for underwater treasure couldn't get any worse, the spirit is free possessing Kai again in the process. He roams Ninjago to find a way to open a mystical portal to let free his "still alive" ancestor spirits to possess the innocence of Ninjago until no human is left unturned. Much responsibilitied are put onto Gizmo's, Zane's adopted son, shoulders. Can Gizmo and the team conquer his spirit, or get possessed trying..?