This study focuses on a chance meeting between Gawain, Ywain, Marhalt, and three damsels in book 4 of Sir Thomas Malory’s Morte Darthur . The aim here is to consider the relationship between arbitrariness and literary knowledge in Malory’s romance. In this examination I trace the close connection between etiology and style in the passage under discussion, looking to Malory’s French source, the Suite du Merlin , to show how he produces arbitrariness through precise semantic and stylistic choices. Ultimately I attempt to demonstrate how arbitrary moments in the Morte Darthur show Malory at his most original and stylistically sophisticated. Arbitrariness, as an effect of particular narrative strategies, leads to the production of new knowledge, of the kind only accessible in the experience of reading literature.