A unique combination of children's literature and a travel book, where indirectly, through the plot and the adventures of the heroes, the sights and monuments of each area are presented, along with elements about the history, geography, and culture of the place. The explorer-professor Iguana Jones is a real person, more real than the author of this book. Together with his inseparable iguana, Montezuma, a group of four children, and the invisible Reader, they undertake the most dangerous missions. An unexpected adventure awaits the secret group in Athens. Will they manage, with the help of the magical map, to retrieve Theseus's ring from the would-be antique thieves and return it to the museum? The Black Beetle and the Pink Dragonfly have a different opinion.