So, that was a thing that happened, huh? After lots of meandering, the story of the Death of Arthur really got started in Book XX, and in Book XXI we have the deaths not only of Arthur, but also Gawaine, Launcelot, and Guenever. Plus we finally get to see a little bit of Sir Mordred, and while we spend only a single chapter with the man, I think we do get a sense of just how much of a dick he is.
The first of the four big deaths in this book is Sir Gawaine, who dies in the midst of Arthur’s army capturing Dover. After Gawaine spent the back half of Book XX taking massive amounts of punishment and defeating dozens of knights, it’s a little surprising that his final battle occurs off-screen and with anonymous foes; by the time Arthur finds him he’s already dying. But even so, he gets to pull one last classic Sir Gawaine screw-up: writing a letter exhorting Launcelot to come fight Mordred with Arthur. By the time Launcelot gets the letter, Mordred and Arthur may both be dead already, and certainly Launcelot disregards the letter as a cheap ploy.
Then from beyond the grave Gawaine brittas it again*, and tells Arthur to delay because surely Launcelot is on his way, and what happens? Arthur’s doom comes whether Arthur’s ready or not, big battle, and Arthur dies. Or travels to the magical island of Avalon; Malory seems to want to have that one both ways, what with the magical boat bearing him off together with Morgan and Nimue, and also with Bedivere and the Archbishop of Canterbury founding a monastery at the site of Arthur’s tomb. This Book is the only one wherein Malory admits he doesn’t have a solid grip on the French romances he’s translating, because they all disagree with one another about Arthur’s death and final fate, and the final fates of Bors and the handful surviving brethren of the Round Table.
He’s sure about one thing though: Guenever is a great nun. She changes the way people think about nunning! And I can believe it, mainly because Malory has had so few good things to say about Guenever since her introduction back in Book III. So if he’s willing to call her a great nun, then she’s a great nun, end of story. She’s so great that, even though her star-crossed love for Launcelot drives her to faint three times when they meet again, she declines his offer to run off to be the Queen of France with him. Instead she stays in the convent and runs out the clock, which so upsets Launcelot that he goes off and becomes a monk, too, out of spite as much as anything.
So that’s the great love story of medieval romance: her husband dies, she declines to remarry her longtime lover; they both become religious ascetics and eventually die. And Sir Gawaine is just the worst.
* Gawaine gets no respect. “Knock knock! Who’s there? Cancer! Oh, good, come in, I thought it was Sir Gawaine!”