The Mystery Inc. gang have gone their separate ways and have been apart for two years, until hey are mysteriously joined together to solve a case on Spooky Island. Not knowing that the others have also been invited, they show up and discover an amusement park that affects young visitors in very strange ways. But is the island really haunted, or is there just a sinister individual behind all the ride malfunctions and creepy, crawly creatures? If so, who could it be? Fred, Daphne, Velma, Shaggy and Scooby soon realize that they cannot solve this mystery without help from each other.