In 1492 victorious King Fernando of Aragon forces the daughter of the last Muslim ruler in Andalusia to become his concubine as a gesture of "reconciliation." The product of their coupling, a secret Muslim with an abiding hatred for his father, founds a line that nurtures the flame of vengeance through the centuries. Disillusioned by Spain's failing fortunes in the 30-Years-War, Eduardo Macías leaves the Army of Flanders and sets out for home. Eduardo's reputation as a valorous soldier leads to his being named Captain of the Santa Hermandad, a Spanish force charged with protecting the people and maintaining the law. He is forced to accept a mission by officials of the Holy Inquisition to investigate an alleged case of heresy involving a nobleman with ancient royal ties. What Eduardo discovers places him in a dangerous situation at odds with the Inquisition, and he must choose between upholding his honor and excommunication.