Brethren is the story of Will Campbell, coming of age in a time of conspiracy, passion, politics and war. Will longs to become a Knight Templar, but first he must serve as an apprentice to the foul-tempered scholar Everard, a man of dangerous secrets. Meanwhile, a new star is rising in the east. Amir Baybars has fought his way from slavery to become a fearsome commander, driven by an unquenchable desire to free the Holy Land from the European invaders.