The narrator introduces the next tale, in which Arthur will face a Sable Knight and receive the legendary sword Excalibur by meeting a Lady at a Lake of Enchantment.

In spring, Arthur and his Court travel through the Forests of Usk and stop to rest in the shade. At this time, his Court includes Kay, Gawaine, Ewaine, Pellias, and seven other knights. A wounded knight in white and azure—later named as Sir Myles of the White Fountain—approaches the group on horseback with his page. Arthur orders his knights to help the injured man. After he is treated, the injured knight is brought to Arthur’s pavilion with his page.

The page and Sir Myles came from the north seeking adventure. Myles defeated six other knights in a fortnight (14 days). That morning, they discovered three damsels tossing a ball in front of a castle. When they learned he was in search of adventure, one damsel gave him directions to a bridge. Myles and his page followed the directions and found a castle beyond the bridge. On the bridge was a black shield with a brass hammer, and a sign indicating that whoever hits the shield does so at his peril.