To such a vile extremity had love, jealousy, and despair brought the brave knight Tristram de Lyonesse, that from being the fellow of lords and nobles he became the butt of churls and cowherds. About this time it happened that Dagonet, the fool and merry-maker of King Arthur, rode into Cornwall with two squires, and chance brought them to a well in the forest which was much haunted by the demented knight. The weather was hot, and they alighted and stooped to drink at the well, while their horses ran loose. As they bent over the well in their thirst, Tristram suddenly appeared, and, moved by a mad freak, he seized Dagonet and soused him headforemost in the well, and the two squires after him. The dripping victims crawled miserably from the water, amid the mocking laughter of the shepherds, while Tristram ran after the stray horses. These being brought, he forced the fool and the squires to mount, soaked as they were, and ride away.
But after Tristram had departed, Dagonet and the squires returned, and accusing the shepherds of having set that madman on to assail them, they rode upon the keepers of beasts and beat them shrewdly. Tristram, as it chanced, was not so far off but that he saw this ill-treatment of those who had fed him, and he ran back, pulled Dagonet from the saddle, and gave him a stunning fall to the earth. Then he wrested the sword from his hand and with it smote off the head of one of the squires, while the other fled in terror. Tristram followed him, brandishing the sword wildly, and leaping like a madman as he rushed into the forest.
When Dagonet had recovered from his swoon, he rode to King Mark's court, and there told what had happened to him in the wildwood.
"Let all beware," he said, "how they come near that forest well. For it is haunted by a naked madman, and that fool soused me, King Arthur's fool, and had nearly slain me."
"That must be Sir Matto le Breune," said King Mark, "who lost his wit because Sir Gaheris robbed him of his lady."
Meanwhile, Kehydius had been ordered out of Cornwall by Queen Isolde, who blamed him for all that had happened, and with a dolorous heart he obeyed. By chance he met Palamides, to whom the damsel had reported the sad condition of the insane knight, and for days they sought him together, but in vain.