Dracula, Mavis, Johnny and the rest of the Drac Pack take a vacation on a luxury Monster Cruise Ship, where Dracula falls in love with the ship’s captain, Ericka, who’s secretly a descendant of Abraham Van Helsing, the notorious monster slayer.

When Van Helsing's mysterious invention, the "Monsterfication Ray," goes haywire, Drac and his monster pals are all transformed into humans, and Johnny becomes a monster. In their new mismatched bodies, Drac and Johnny must team up and race across the globe to find a cure before it's too late, and before they drive each other crazy.