If you want to read about this whole tournament thing, better check out Malory, because once again, this book's so not into those minutiae.
Lancelot does fairly well at this tournament (once again in disguise, his usual modus operandi), although in the end his old Mador wound bursts open, he's stabbed by a spear, and leaves the field barely able to sit on his horse.
Flashback time! Because he feels sorry for her, he can't bear to tell Elaine that he's not here to stay.
So, he agreed before the start of the tournament to wear Elaine's token—a red sleeve embroidered with pearls. It has taken her twenty years to embroider this sleeve.
Lancelot claims that this token will make his disguise more legit, since he never wears tokens at tournaments.
Back to our normal timeline! Elaine helps nurse Lancelot back to health after the tournament is over.
Back in Camelot, Guenever has heard all about this red-sleeve-wearing incident. She talks to Sir Bors about how Lancelot has totally betrayed her.
She says it serves him right to get wounded, since he was wearing that sleeve. Bors argues, and tells her that he was betrayed by being attacked by three knights at once.
And, back in Corbin, Elaine still thinks Lancelot is here to stay.
He's getting ready to have a really hard conversation with her.