Scooby-Doo and the gang are on the case when a mysterious lake monster starts scaring the guests at a summer resort in Erie Point, where Fred, Daphne, Velma and Shaggy have taken on seasonal jobs to pay for a barn they accidentally burned down. But in addition to sneaking suspicions, there's some romance in the air.

Unjustly accused of staging a spooky practical joke complete with ghosts, Daphne, Velma, Fred and Shaggy are suspended from Coolsville High. To clear their names, they team up to solve the supernatural mystery…and head straight into nonstop laughs and adventure.