Six months later, Arthur and his army are besieging Lancelot's castle, Joyous Gard.
Inside, Lancelot is talking to Guenever about how he doesn't understand how he killed Gareth and Gaheris. He loved them—especially Gareth.
Overcome with guilt, Lancelot recognizes it was his fault, because he was flailing around at the crowds with his sword. He was going for even the foot soldiers, and not sticking with the knights.
Now, Gawain is out for blood, and has bullied Arthur into coming to fight against Lancelot. He's even made up a little tune that they chant every so often: Traitor knight / Come out to fight. / Yah! Yah! Yah! Wow. Those lyrics are… not good.
There have been periodic fights, and Lancelot has been winning, but hasn't killed anyone. He keeps begging them to just go home.
Guenever says she'll just go back, even if she'll get burned at the stake, but Lancelot tells her it would be worthless. The feud has now gone too far—and it goes a hundred years back. Eventually, even Sir Urre of Hungary would get involved, because he's just that grateful to Lancelot for healing him that one time.
What the heck, he finally admits. Maybe it would be better if Arthur just took Guenever back and went on his way.
Well, Guenever says, they could always go to the Pope and see if he would do something about it.