It appears Shaggy and Scooby's dreams may have come true when Shaggy accidentally crashes the Mystery Machine into an ice cream factory, but the dream soon turns into a nightmare when three phantoms try to scare them away.
The gang must investigate an old prison where the ghost of Iron Face lurks after their friend is kidnapped.
The gang goes to visit their friend Antonio in Venice, Italy, and find that he's haunted by the ghost of an ancestor, the Ghostly Gondolier, who seeks to steal the ancient necklace/family heirloom Antonio wears!
The gang decides to visit their pal, Professor Brickston in the lost city of Byzantius, Turkey. The city is so lost that the only residents are the professor, his helpers and of course, the Tar Monster.