When the hopelessly lost members of Mystery, Inc. enter Moody Manor to ask for directions, Don Knotts, the world's greatest detective, mistakenly believes that they are the relatives of the estate's wealthy late owner. Don suspects that one of them murdered Captain Moody!

As Sandy Duncan's latest movie, a remake of "Dr. Jekyll and Mr. Hyde," films on a studio lot that is soon to be closed, the risky business of moviemaking becomes more risky than usual. A woolly creature disrupts the filming! Scooby and the members of Mystery, Inc., investigate the strange events.