A comprehensive examination of the enigma of the Templars and their lost treasure based on original source documents.• Considers the possibility that the medieval castle of Gisors hides the Templar treasure.• Examines all the evidence for a secret order within the Templars, whose heretical ideology brought down the wrath of King Philip of France.When French King Philip the Fair ordered the arrest of the Knights Templars and the confiscation of their property in 1307, the Templars were one of the most powerful forces in Europe, answerable only to the Pope. It was also one of the richest, despite its knights' vow of poverty. Yet not a penny of their immense treasure was ever found. The hunt for this lost treasure has centered on a number of locations, among which is the medieval city of Gisors, a site on the Normandy and French border that is honeycombed with complex underground passageways and chambers. Mysteriously, all attempts to discover what may be concealed in these subterranean corridors are rigorously discouraged by contemporary authorities. The enigma of the treasure is but one of the many unsolved mysteries concerning this order that continues to haunt our imaginations. Who were these "poor knights of Christ" who made denial of Jesus a requirement of acceptance into the order? What were their true purposes and what was the nature of their secret that drew the wrath of the king of France down on their heads? Was there really a treasure and, if so, what was it--material wealth or something more powerful, such as the Holy Grail or the secret to the philosopher's stone? Was there a secret order within the order that authorized the heretical practices for which they were condemned? In a search for answers to these and other questions, Celtic and medieval scholar Jean Markale goes back to original source documents in an attempt to clear away the baseless assumptions that have sprung up about the Templars and to shine new light on their activities.