When Gaspar's mother, Elvira, marries family lawyer Peter Cawthorne, Gaspar plans a luxurious holiday for the family on his refurbished yacht, Floridablanca. The destination is Mexico's historic Yucatan to visit "Huayrocondo," the seaside hacienda, Gaspar's inherited from his great-uncle, Charlie. Gaspar and his side-kick, Alex Mendoza, visit many ancient Mayan sites in the Yucatan peninsula. That's when the trouble starts! The intrepid teenagers stumble across a gang of antiquities thieves. The thugs pilfer golden objects for the notorious, "Jaguar" the mastermind who is wanted by Interpol in connection with thefts of ancient relics from around the world. Join Gaspar, Alex, Elvira, and Peter, along with their questionable Mexican guide, Roberto, and Floridablanca's loyal captain, Craig Cadawalader. Meet Hanuman, a suspicious new-age adventurer, who takes the boys diving in spooky, phosphorescent Cenotes-deep pools of danger. Will they catch the Jaguar? As if crooks aren't enough to watch out for, Gaspar also has The Lost Temple of Chac Mool to consider, and so many amazing Mayan treasures to uncover and recover, too. Open the book and join our heroes, along with ghostly Uncle Charlie, as you discover the Mystery of the Yucatan Legacy.