Scooby-Doo, Shaggy and the gang arrive in Atlantic City for a relaxing vacation...and land center-stage in a three-ring mystery! After visiting a shuttered big top that's being hounded by werewolves, the gang goes undercover to find out why. It's up to Daphne the clown, trapeze artist Fred, Velma the human rocket, ringmaster Shaggy and the amazing trick dog Scooby-Doo to solve the mystery and save the circus.