Malory wants to talk about Tristram again, he’s decided. The tournament he was just now talking about was a massive success, so naturally Galahalt and Bagdemagus decide to have a second one. They’re hugely jealous of Launcelot (even though he’s been Bagdemagus’s friend in the past) and this second tournament is just a ploy to lure Launcelot out of hiding so that they can get him with all their knights in a big ol’ dog-pile.
Mark hears about this plot, on the villain grapevine, and decides he’ll use it to get Tristram killed. He goes to Tristram, tells him about this tournament, and suggests that Tristram really ought to do the cool thing that all the cool knights are doing nowadays, and go in disguise.
Tristram, being dumb as a post, readily agrees. He shows up at the tournament, Mark points to him and shouts “look, it’s Launcelot in disguise!”, he gets jumped, bing bam boom. End result: Tristram needs a few months of convalescence. Mark acts all abashed that Tristram got hurt (really he’s abashed that Tristram survived) and takes him to a hospital-castle. Then as soon as everyone’s back is turned, Mark transfers Tristram to a jail-castle.
So he was there a great while, much like the time he and Palomides and Dinadan were locked up together in Sir Darras’s dungeon. The lovely Isoud notices that he’s not around, and has Sir Sadok, the Cornish Vulcan, seek Tristram out. Sadok figures out where Tristram is, and sets up an ambush with two of his cousins, outside the prison.
Mark comes along with four of his nephews, Sadok jumps out, kills all the nephews, but loses one of his cousins in the process. Then Sadok rides off and finds Sir Dinas, and fills him in on the situation.
Dinas is aghast that Mark continues to make trouble, even after he promised on a book he wouldn’t. He and Sadok decide to raise an army and revolt against Mark, because this has all just gone too far!
Mark finds out about the revolt, and panics, of course. He comes up with a plan, though! He forges a letter to himself, from the Pope.
“Darling Mark,” he writes. “Come participate in the Crusades. Love, the Pope. PS Bring Tristram.”
He sends a copy of the letter to Tristram, hoping that Tristram will read it, decide he’s needed in the Holy Land, and leave Cornwall. Once Tristram is gone, Mark hopes, everything will go back to normal.
Tristram, in prison, reads the note. He’s free to go, Mark’s messenger tells him. Mark will be along later.
“Screw that,” says Tristram. “Mark’s a dick and I’m tired of his bull hockey. This is an obvious forgery, because the First Crusade isn’t until the eleventh century and while Malory wrote in the fifteenth century, this story is supposed to be set during the fifth century!”
So the messenger goes back to Tintagil and tells Mark that Tristram has seen through his ruse. Everyone in Tintagil is bandaged up and wounded, what with the revolt going on in the background: one knight has his neck nigh broken in twain, another has his arms stricken away, third knight borne through with a spear, and one guy has his teeth stricken in twain.
“Why don’t we just surrender?” is the question on everybody’s lips, at Tintagil. None of them are particularly gung-ho about defending Mark’s right to rule. Mark is a dick.
“You’re a bad, bad man,” says Sir Percivale, who happens to be visiting. “You’re very mean to Tristram, just because your wife and he are in love! Are you so bad a man as to assume that Tristram would be bad, too, and have an affair with your wife? Are you so bad you think the lovely Isoud would cheat on you? For shame, Mark, for shame!” And then Percivale wanders off.
Mark thinks about what Percivale said. “If I was good like Percivale,” he thinks, “then people would like me and not revolt against me!” So he sends a message to Dinas, saying he’s going to go fight in the Crusades for realsies.
Dinas hears that, he stops the revolt immediately! But it’s a ruse. Mark has Tristram thrown in prison again!
And at this point the lovely Isoud has finally had enough! She packs up her things (including Tristram) and announces she and Tristram are leaving Cornwall.
“This country is dreadful,” she says. “You people are all the time arresting Tristram, exiling him, I mean, it’s getting so a girl can hardly have an affair around here. Dinas, Sadok, you fellows have Mark killed, or arrested, I don’t care. Do whatever. My boyfriend and I are leaving.”
And they leave! And Dinas has Mark arrested!
Apparently that was all it took. I don’t know why the lovely Isoud didn’t try it, like, a hundred or so chapters ago!