Having failed in their search for the Holy Grail, the knights of the Round Table return to Camelot in dwindling numbers. As he observes a rift between Lancelot and Mordred, Arthur begs his knights to set aside their disagreements and become friends. However, the monarch is unaware that Lancelot is having an affair with Guinevere. Lancelot is divided between his devotion to his king and his love for the queen, while Mordred is intent on using Lancelot's infidelity to harm him.