The author has solved the riddle that has mystified enthusiasts and experts alike all over the globe for more than four decades! As a result, he has discovered, and photographed, the actual keystone, the existence of which has been the subject of fierce speculation. Contrary to the fictional riddles that have been employed in other popular writings, this riddle relates to an authentic secret document of the Rosicrucian Order, the Priory of Sion, entitled Le serpent rouge – which appears to be the 'map' to nothing less than the temple treasures of Jerusalem. This is the title everyone even just remotely interested in the enigma surrounding these treasures, as well as the holy grail, has been waiting to read.