Tristram, too, prepares to go to the Pentecost feast. Isode refuses to go because her appearance as his lady would make men challenge him to fights. Tristram must not stay away though, she says, because his station requires him to go. Tristram goes and on the way meets his old enemy Palornydes. They fight, then for the last time drop their quarrel and vow to be friends henceforth. Palomydes, having now fulfilled an old vow involving seven great battles, agrees to be christened.
The Tristram section of Le Morte d'Arthur takes up nearly a third of the total work and seems from a modern point of view an enormous digression: Arthur's knights figure in the Tristram story, but centrally the plot concerns not Arthur's court but that of a petty vassal to Arthur, King Mark. To the medieval reader, with his different but no less sophisticated esthetic expectations, the Tristram section would seem not a digression but a parallel, a second story juxtaposed with the first to serve as an exploration of the first story's meaning. The Tristram story rings changes on the whole Arthur story; that is, it presents every possible variation on the themes set up in the Arthur story, with the ultimate purpose of demonstrating dramatically that, whatever the particulars may be, once one has entered the trap of glory and chivalry, there is no way out.
Tristram's story in some ways recalls Arthur's: born while his father is presumed dead, Tristram is nearly slain by servants who would like to rule the barony themselves; he is aided by Merlin and raised by foster parents; one of his first accomplishments is to overthrow a claim for tribute; and as Arthur kills a giant who has murdered the wife of his cousin, Tristram kills a giant who has murdered his cousin.
In other respects Tristram's story parallels that of Launcelot (part of whose story has not yet appeared in Malory's legend): both run mad from love-despair; each loves the queen of his respective lord; both are trapped in bed by knights jealous of their personal glory; both are driven out of court when their adultery is proved; both plead (in identical phrases) for pardon because of their long service to the state; each triggers civil war but later becomes crucial to his lord's defense of his kingdom against enemies: Tristram, pardoned by Mark, saves Cornwall, while Launcelot, not pardoned until too late, cannot move his forces to England in time to save it.
There are countless parallels of this kind, not only in the main plots but in even the most trivial incidents involving minor characters. The story of La Cote Male Tale, who ends up happily married, closely parallels Gareth's story — but with grim complications introduced by the fact that nearly everyone he meets is in disguise. Lamerok's love for King Lot's widow (Gawain's mother) and Palomydes' love for Tristram's mistress (King Mark's wife, Isode) ironically comment on the love stories of Tristram and Launcelot. Lamerok's love, which shames the lady, intensifies the Lamerok-Gawain feud. Palomydes' futile love for Isode, like Tristram's love for the same lady and like Launcelot's love for Guinevere, makes the ]over a valorous fighting man but also involves him in wrong causes.
Mark's story, too, comments on the Arthur story. King Mark is stupid, cowardly, and thoroughly vicious; but though he is comically incapable of winning any glory on his own, he is driven by the same motive as any bold knight: desire for glory greater than any other man's. He may not kill those who stand above him by honest battle, but he manages to get rid of them, or some of them. (Eventually he even manages to bungle through a successful murder of Sir Tristram.)
One of the central symbols organizing these parallels is the idea of disguise. Every knight rides in disguise at one time or another in the Tristram section, and the apparent reason is that the chivalric system is overripe. The great knights who won their legitimate glory in war against the infidel, in defense of the kingdom, or in defense of the innocent — such men as Launcelot, Gawain, and Lamerok — are now too well known and too much feared to add to their glory (as they must do to hold their ladies' interest) in the old way. Since all men now fear them, they no longer change their shields as a sign (or even pretense) of humility; they change them in order to dupe poor fools into fighting. Cowardly knights, on the other hand, change their shields to escape the vengeance of the relatives of those they have murdered or killed in more or less legitimate battle. Thus great knights, disguised, slaughter or maim one another in the challenge game or defending the innocence of their far from innocent ladies, while wicked knights, also disguised, prey on the weakened and on strays.
Superficially, this insanity seems glorious, a colossal sort of football, and Sir Dynadin's voice of common sense seems ludicrous. Riding with Tristram, Dynadin curses the day he fell into the company of this battle-happy fool who can never pass a knight without trying him or circle a castle where knights insist on challenging all who pass by. When Isode flirtatiously asks Dynadin how he can ever become a great knight if he won't fight for the love of some lady, Sir Dynadin's answer is comically blunt: "'God deffende me!' seyde sir Dynadan, 'for the joy of love is to shorte, and the sorow thereof and what cometh thereof is duras over longe.'" And when Isode goes further, teasingly asking if he will fight for her against three cruel knights, Dynadin replies: "I shall sey you ye be as fayre a lady as evir I sawe ony, and much fayrer than is my lady quene Gwenyver, but wyte You well, at one worde, I woll nat fyght for you wyth three knyghtes, jesu me defende!" He is comic because he won't play by the rules; but as the rest of the Morte d'Arthur makes clear, he is right.
The Tristram section does directly develop one important strand of the Arthur story. The Lamerok-Gawain feud is intensified, and allegiances on each side are made firm through tournaments and encounters in the challenge game. When Gawain and his brothers learn that Pellanor was not the murderer of their father — they only "denied" he was — they have already gone too far to back down. Appearance has become reality; the disguise has become the man.