Part of the Karito Kids Adventure series, Mexico Mystery follows the story of 11-year-old Pita, a girl of privilege from Mexico City who bucks the rules of her social class after her beloved horse goes missing. When Pita goes on a search for her horse, she finds more than she could have ever expected - a new friend in the stable hand's daughter, her grandfather's humble heritage, and a mysterious uncle she didnt know existed. Perhaps most importantly to Pita, though, is the strength she finds within herself and the understanding she gains of her horse's desire to run free. As with all Karito Kids Adventures, the books interact with the Karito Kids website and allow kids to activate a donation to a childrens charity online.