Guenever is waiting for Lancelot at her room. She is aged, but still resplendent. Lancelot enters and begins to brush her hair. Lancelot tells her about Gareth's warnings and Guenever is frightened, she thinks maybe the brothers have forced the king's hand. She thinks she hears someone at the door; Lancelot bars it. They talk about the brothers' hatred for Lancelot. Guenever suddenly pales and leaps up—she tries to force Lancelot from the room realizing Gareth's warning is true.
Lancelot has become arrogant and is blind to Gareth's warnings—although Guenever is not. Lancelot believes Arthur would not betray them, but underestimates Arthur's adherence to justice even above loyalty to his loved ones.
They see the handle of the door move softly upwards. The handle falls back and there is a loud, iron knocking on the door. Agravaine's voice cries: "Open the door, in the King's name." Lancelot realizes he has forgotten his sword and has no armor. He picks up a footstool, winds a black cloak round his right hand to protect it and kisses Guenever good-bye. He puts his shoulder to the door, jerks it open to allow one knight through and quickly slams the door shut again.
Gareth was right and the brothers have trapped Lancelot so they can gather evidence to accuse the lovers of treason.
Lancelot takes the knight's sword from behind, pushes him to the floor, bangs him over the head with the stool and quickly pierces the knight's body with the sword. They lift the visor once he is dead; it is Agravaine. Quickly Guenever dresses Lancelot in Agravaine's armor. The lovers exchange rings and Lancelot promises he will come for her. Lancelot opens the door to reveal a passage crammed with knights.
Lancelot's knightly skills are put to the test and he kills Agravaine. Agravaine's death will only further the hatred and feud between Mordred and Arthur.