 It is set primarily in Cornwall, and is Sutcliff's retelling of the Tristan and Iseult legend.Sutcliff tells the story again in an almost identical manner, albeit greatly shortened, in a chapter of her later Arthurian novel "The Sword and the Circle" (1981).Tristan is depicted as a prince of Lothian, whose father, King Rivalin married the sister of Mark of Cornwall, making Tristan the nephew of King Mark.