The gang is going to meet Velma's uncle at his cabin. They get worried when they find him gone and the cabin ransacked. While looking for Velma's uncle, they see something monstrous flying in the sky.
While out on an ocean sailing trip, the gang run into a hurricane and end up stranded on a deserted island that is seemingly inhabited by skeleton-like aliens.
The gang go to visit their friend, Professor Kreuger, who is working at the North Pole. However, they arrive only to discover that he's disappeared. It turns out, a fur covered dinosaur is wandering around, and may be the reason for the professor's disappearance.
The gang travels to Salem to visit a friend, Arlene Wilcox, on Halloween night. However, the town is being haunted by a witch, and the townsfolk suspect Arlene, who is a descendant of the witch in question.
Mystery Inc. travel to Scotland to help Velma's friend, Aggie McDuff, at her ancestral home, Castle McDuff. Aggie has turned the castle into a tourist attraction, but it is being haunted by the ghost of her great-grandfather, Finnyan McDuff.
While visiting Daphne's Aunt Olivia, who lives in York Towers, a thieving cat creature robs jewelry stores late at night. Aunt Olivia becomes suspected of being the creature, transformed by a glowing medallion in her possession.
While visiting Vulture's Claw Botanical Gardens, owned by one of Velma's friends, Professor Greer, the gang confronts a seven-foot-tall praying mantis that roams the grounds.
The gang go to Decade Records recording studio to watch a live recording of their friend, Jimmy Lewis. But the building is haunted by the Phantom, who is trying to find a song by a missing writer, and will stop at nothing until he gets it.
The gang travel to China making their way to the city of Rampoo. While there, the gang run into the Moon Monster, whose shadow, legend says, turns people into stone.
The gang visit their friend, Antonio, in Venice, Italy, and find that he's haunted by the spirit of an ancestor, the Ghostly Gondolier, who seeks to steal the ancient necklace Antonio wears.
The gang head to Puerto Rico for a holiday. They visit an ancient fortress where the ghost of General Juan Carlos, who guards the El Moro Fortress, warns them to stay away.
While touring England, the gang come upon tennis star, Jimmy Pelton, who's been cursed by Anthos, a warlock, and told to forfeit the Wimbledon tournament.
