Scooby-Doo and the Mystery Inc. travel to Scotland to visit Daphne's relatives at Blake Castle, which is situated on Loch Ness, home of the legendary creature who has recently been stalking Daphne's cousin Fiona. The gang teams up with scientist Penelope Miller, who, after her first sighting of the beast a few years ago, left a prestigious job at the Scotland Natural History Museum to track down the infamous monster. Meanwhile, Scooby and Shaggy unwittingly display athletic prowess and are coaxed into participating in the Highland Games, an annual Scottish sporting event. This year the games are to be held at Blake Castle... unless Nessy gets her way and ruins the games for good!