In the chaotic aftermath of the fall of Acre in 1291 and the reconquest of the Holy Land by the Moslems, the last survivors of the Order of the Temple make their bloody retreat from the Middle East. Loading the treasure of their Order into a decrepit, leaky vessel, they set sail for Europe, where, unbeknownst to them, King Philip of France plots their destruction.

Among their number is Beltran, a native of the Holy Land, who has led the life of a soldier-monk for the past thirty years. World-weary yet incorruptible, Beltran is guardian both of the treasure and the Rule of the Order. As his companions' loyalties waver, he struggles to keep the faith, only to witness the end of the Order as the Templars are thrown to the Inquisition and their Grand Master burned at the stake.