When the family castle is besieged by an ancient enemy, Ursula rides for help to Aylmer, who has asked for her hand in marriage. Ursula admires and respects Aylmer, who is much older than she. He loves her dearly and promises to help lift the siege. Aylmer offers the services of Benedict de Huste, a young man with a tragic past whom Aylmer regards as an adopted son. Together Ursula and Benedict fight a double battle. They fight for their lives in the besieged castle, and they fight against the love which grows between them.