Scooby-Doo and the Mystery Gang visit Oakhaven, Massachusetts to seek strange goings on involving a famous horror novelist and his ancestor who is rumored be a witch.

After going their separate ways, Scooby-Doo, Shaggy, Velma, Daphne, and Fred reunite to investigate the ghost of Moonscar the pirate on a haunted bayou island, but it turns out the…