By these swift strokes, Malory arrives at the introduction of Merlin, agent of Arthur's rise and fall. On the other hand, Malory can switch from swift narration to scenes slowly and carefully worked out. When Arthur draws the sword from the stone, for instance, Kay's lie (his pretense that he himself drew it out), his father's suspicion, Arthur's grief at finding he is not Sir Ector's son, and Arthur's pledge that he will always be faithful to Ector and Kay, are all developed slowly, through dialog and gesture.
But at the heart of Malory's characterization is his original sense of how each character contributes to and defines the total tragedy. He makes Merlin directly responsible for every step of Arthur's progress — even his birth. He seems at first to be a prophet, a direct agent of God. But he is not. He is part demonic tempter, part wizard: he knows necromancy, and he can see into the future, but his vision, like that of any astrologer or (as Lot says) "dream-reader" is imperfect. In medieval terms, he can see into the workings of Fortune but not always into those of Providence. To trust him is to trust not God, but "the World."
Malory's method is to present Merlin first in his best light — manipulating Uther's lust to his own end, guiding Arthur to greater and greater power — then to reveal, little by little, Merlin's dangerous flaws. In the joke he plays on Arthur after the battle of Bedgraine, Merlin appears dressed in the hides of black sheep and offers treasure "under the ground" for a gift from Arthur. Nothing comes of the joke, but it has ominous overtones of demonic temptation. For medieval writers, to trust in the World (whose prophet is Merlin) is to trust the devil, emblematically identified with both black sheep and treasure under the ground. (We learn later that Merlin is a devil's son.) Merlin's deadly mistakes — his failure to warn Arthur against lying with Lot's wife and his still more terrible mistake in the attempted murder of Mordred — reveal how dangerous his limitations are.
