When his ship runs aground on a strange island during a storm, Arthur sets off on his charger to for help and meets a dwarf who tells a curious story about his son and the unicorn who has befriended them both. This story was originally the concluding episode in an Arthurian romance written in France in the late Middle Ages, Le Chevalier du Papegau. The story is retold here for the first time for young readers. The story is also noteworthy because it is one of the few unicorn stories in which the unicorn is portrayed as female.