At the end of his penance term of 20 years, Templar Arn expects to return home with an honorable discharge from the late grandmaster after a last desert mission, during which he must defeat fellow knights to prevent Bedouin allies being slaughtered. The grandmaster's successor tears it up, claiming victory over Saladin is at hand and imposing foolish risks. In Sweden, his bride Cecilia is offered to succeed the wicked abbess, who dies cursing her for refusing to forgive. However she chooses to leave, visit their son Magnus, now a man, and seeking to find and marry Arn at last.