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.