In Bedegraine, it is the night before the battle. Merlyn is concerned that he has forgotten to tell Arthur something—they have spoken about the battle, about Guenever and Lancelot, about Arthur's sword Excalibur and about his father. Instead of what he can't remember, Merlyn tells Arthur a fable: a man was walking in Damascus when he came face to face with Death. He was frightened and so rode all night to Aleppo. The next day, Death taps him on the shoulder; the man is surprised and Death explains that the day before in Damascus, Death had been surprised because he had been told to meet the man in Aleppo.
The fable Merlyn tells Arthur illustrates the novel's attitude towards fate and destiny. Arthur is a fated figure. Arthur, just as the man in the story does, seeks to avoid this fate, but ultimately these efforts only lead him to that same fate. Interestingly, Merlyn's telling of this fable of fate is itself a part of Arthur's fate, as the thing that Merlyn has forgotten to tell Arthur—his mother's name—would later alert Arthur to the fact that Morgause was his half-sister, which may have stopped her from being able to seduce him, and therefore meant that Mordred would never have been born.
Arthur reflects on this and realizes that destiny is something you cannot elude. Merlyn decides to tell Arthur something else—that when he is dead, his tomb will say: Hic jacet Arthurus Rex quondam Rexque futurus. This translates as: The Once and Future King. The King is silent; he wonders if they will remember his table; he wonders what sort of people the people of the future will be.
This is the first mention of the idea of Arthur as a "future" king. This title may suggest that Arthur will arise again to rule longer after he dies. But the notion of the future king may also refer to the fact that Arthur is ahead of his time, a political innovator whose attempts to reform justice will fail but will improve the state of humanity in its attempt.