Collum swims ashore on the Cornish beach, exhausted but armed with Excalibur. He finds Lancelot's troops have captured Bedivere, Palomides, Nimue, Dinadan, and Guinevere, with Merlin overseeing them. Lancelot, dressed in imperial regalia, is rallying his soldiers, possibly to execute the prisoners. Collum reveals himself, drawing Excalibur, which startles the troops.

Merlin attempts to discredit Collum by magically lighting Lancelot's sword Arondight, claiming Excalibur is a fake, and slanders the captives. Collum challenges Lancelot to draw Excalibur from its scabbard; Lancelot refuses and instead agrees to a duel. Before fighting, Collum receives encouragement from his friends—Bedivere expresses faith in him, and Nimue gives him her green ribbon as a favor and kisses him.

The duel begins disastrously for Collum, who is outmatched by Lancelot's superior skill. He loses his little finger and half his ring finger in a desperate disarm attempt. Wounded and despairing, Collum nonetheless finds inner strength, recalling his hardscrabble origins. He abandons chivalrous fencing for dirty brawling, channeling Arthur's spirit and his fairy blood, and feints by letting Lancelot snatch Excalibur—then breaks Lancelot's nose with a left hook.

In the ensuing brawl, Collum beats Lancelot down with fists, headbutts, and the pommel of Excalibur, finally pinning him with the sword to his throat. Guinevere's voice calls him back from killing rage, and Collum spares Lancelot, ordering the prisoners freed. Soldiers comply.

As Merlin steps forward, smiling, ready to orchestrate Collum's coronation, Dinadan stabs him through the back with Arondight, killing the ancient wizard. Refusing the crown himself, Collum proclaims Guinevere Queen of Britain and offers her Excalibur. She accepts, raises the sword, and the soldiers gradually take up the cry. Bedivere kneels first.