Tristam (also known as Tristan), who is son of King Melyodas de Lyones and the sister of King Mark of Cornwall, is then introduced, and his adventures unfold. He kills Sir Marhault to free his uncle from a debt owed to King Angwyssh of Ireland, and then falls in love with Isode (also known as Isolde), Angwyssh's daughter. Isode marries Tristam's uncle Mark, but Tristam and Isode remain lovers. Tristam is exiled by Mark, which means he can no longer use his true identity; thus, he fights as The Knight with the Black Shield. Tristam duels and beats many of Arthur's knights, but is eventually thrown in prison and becomes ill. He escapes and eventually meets and fights Launcelot in a duel predicted by Merlin. They become the best of friends.
Launcelot, who is in love with and completely loyal to Guinevere, rides one day in search of adventure. He kills a dragon, sees the Grail, and is tricked into lying with Pellas' daughter Elayne, with whom he has a son, Galahad. Guinevere, upon hearing of the affair, has Launcelot banished from court; Launcelot then wanders from place to place in his grief. Elayne, through her father, heals Launcelot through the Grail, and he eventually returns joyously to Camelot and the Round Table.
Launcelot introduces his son, Galahad, to the court, and Galahad takes the Sege Perilous, the seat at the Round Table that no knight has been worthy enough to fill. Galahad also draws the sword from the floating stone, establishing him as the best knight in the world, but also accepting the sword's curse — that it will later cause a grievous wound.
