Tristram and Larnerok meet again by accident, this time in the Perilous Forest of North Wales. They unwittingly fight each other, then again swear friendship. They meet Palomydes, who unhorses them both and rides on in pursuit of his beast. Now Tristram and Lamerok part and undergo separate adventures, many of them involving single combat with Round Table knights.
Arthur is in the Perilous Forest through the craft of a sorceress, Aunowre, who captured him to make him her lover and, finding he will not be faithless to Guinevere, now hopes to destroy him by sending him, without his identifying arms, against all the knights who, to increase their glory, fight any who happen to pass. Arthur's knights, here to hunt for him, are unwittingly his most dangerous enemies.
Tristram meanwhile reaches Cornwall and Isode, discovers love letters that have passed between her and another knight, and goes mad. He runs naked for a time, then recovers and is exiled by Mark. In exile he encounters the Round Table knights who are looking for Arthur. He beats many of them, helps Launcelot when his life is threatened by Morgan le Fay, helps Gawain, and enters a tournament near the Castle of Maidens.
