Mystery Inc. (Daphne(Sarah Michelle Gellar), Fred(Freddie Prinze Jr.), Velma(Linda Cardellini), Shaggy(Matthew Lillard), and Scooby Doo(Neil Fanning)) has broken up; on the grounds of who has been solving their cases. After two years seperated, they are mysteriously joined together to solve a case on Spooky Island. A theme park owned by a man named, Mondavarious(Rowan Atkinson). He needs their help, figuring out why the vacationers are leaving mellow and sober. But it seems they are brought back as one for more than just solving a case.