Based on the work of the enigmatic twentieth century alchemist Fulcanelli, the authors show how the greatest alchemical secret is that of time itself, and that coded into an obscure monument - the cross in the town square of Hendaye - in southwestern France is the imminent date of the apocalypse. Their explorations take them from Hendaye to the western facade of the cathedral of Nortre Dame, to the Pyrenees, ancient Egypt, and the origin of Atlantis in Peru.