In 1119, nine knights led by Hugh of Payns arrive in Jerusalem with a secret purpose: to explore the underground passages of the ancient Temple of Solomon in search of the remnants of the Temple Treasure that the Romans failed to carry away. For nine years, while officially serving as protectors of the pilgrims, they secretly excavate beneath the eastern wing of the compound, facing political intrigue, tensions with the crusader nobles, attacks by bandits, and the watchful eyes of Muslim envoys.
King Baldwin I grants them lodging in the southern wing of the royal palace ?the former Temple? and protects them, though he demands results. Meanwhile, in Europe, Bernard of Clairvaux works to legitimise the new religious-military order.
The novel follows the evolution of the brotherhood, the arrival of new knights such as Robert of Craon, the consolidation of their mission, and the final discovery of a collection of sacred objects: vessels, candlesticks, ritual coins, and Hebrew documents that had remained hidden since the destruction of the Temple.
The epilogue culminates with the audience granted to Hugh of Payns and his companion in Rome, where the Pope bestows upon them the bull granting the White Habit and the Red Pattee Cross, sealing the official birth of the Order of the Temple.
