Through the cloister doors come Sir Gawaine, Sir Gaheris and Sir Gareth. The three brothers are aged, but still the same in all other manners. They have spent the day falconing and Sir Gareth explains in details their endeavors. Mordred, however, is only rude, especially when Gareth suggests he might call his new falcon Lancelotta.
This is the first time we have seen all of the brothers together since they were children in Orkney and cut off a unicorn's head. All, excepting Agravaine and Mordred, are changed; they are kinder and more moral.
Suddenly, the argument escalates and Agravaine pulls a sword on Gareth. Gawaine's old rage explodes and he pulls his own sword on Agravaine. Meanwhile, Mordred with a dagger flashing in his hand, moves to Gawaine's back, but his dagger is stopped in time by Gareth's hand.
Despite this change in them, Gawaine is still unable to curb the instinctive violence in him; he is a reminder that Arthur's idea has failed and continues to fail because Right can never fully curb Might.
It is at this moment, with Agravaine held at the floor with Gawaine's sword, Gaheris holding back Gawaine's arm and Gareth holding back Mordred's dagger, that the King enters the cloisters. He stops while the brothers quickly rearrange themselves, and then moves forward to kiss Mordred.
The scene Arthur encounters is somewhat ridiculous; but Arthur, old and somewhat tired, choses to ignore their dispute. That he kisses Mordred—who at that moment is plotting against him—is an indication of Arthur's personal tragedy. He loves his son, for the simple reason that he is his son, and therefore cannot bring himself to see (or do anything about) Mordred's plotting.