1274: in the fortified city of Acre, the last major stronghold of the Crusaders in Palestine, an epic conflict is just beginning. Will Campbell is a Templar Knight, trained for war; but as a member of the mysterious group known as the Brethren, he is also a man of peace. After years of bloodshed, the Brethren have helped to create a truce between the Christians and Muslims. But Will now fears that they have been betrayed. As war looms, Will is torn between his oath as a Templar, his secret role in the Brethren and his duty to Elwen - the woman he loves but is forbidden to marry.