Book IV - Chapter I - How Merlin was assotted and doted on one of the ladies of the lake, and how he was shut in a rock under a stone and there died.
SO after these quests of Sir Gawaine, Sir Tor, and King Pellinore, it fell so that Merlin fell in a dotage on the damosel that King Pellinore brought to court, and she was one of the damosels of the lake, that hight Nimue. But Merlin would let her have no rest, but always he would be with her. And ever she made Merlin good cheer till she had learned of him all manner thing that she desired; and he was assotted upon her, that he might not be from her. So on a time he told King Arthur that he should not dure long, but for all his crafts he should be put in the earth quick. And so he told the king many things that should befall, but always he warned the king to keep well his sword and the scabbard, for he told him how the sword and the scabbard should be stolen by a woman from him that he most trusted. Also he told King Arthur that he should miss him,—Yet had ye liefer than all your lands to have me again. Ah, said the king, since ye know of your adventure, purvey for it, and put away by your crafts that misadventure. Nay, said Merlin, it will not be; so he departed from the king. And within a while the Damosel of the Lake departed, and Merlin went with her evermore wheresomever she went. And ofttimes Merlin would have had her privily away by his subtle crafts; then she made him to swear that he should never do none enchantment upon her if he would have his will. And so he sware; so she and Merlin went over the sea unto the land of Benwick, whereas King Ban was king that had great war against King Claudas, and there Merlin spake with King Ban's wife, a fair lady and a good, and her name was Elaine, and there he saw young Launcelot. There the queen made great sorrow for the mortal war that King Claudas made on her lord and on her lands. Take none heaviness, said Merlin, for this same child within this twenty year shall revenge you on King Claudas, that all Christendom shall speak of it; and this same child shall be the most man of worship of the world, and his first name is Galahad, that know I well, said Merlin, and since ye have confirmed him Launcelot. That is truth, said the queen, his first name was Galahad. O Merlin, said the queen, shall I live to see my son such a man of prowess? Yea, lady, on my peril ye shall see it, and live many winters after.
And so, soon after, the lady and Merlin departed, and by the way Merlin showed her many wonders, and came into Cornwall. And always Merlin lay about the lady to have her maidenhood, and she was ever passing weary of him, and fain would have been delivered of him, for she was afeard of him because he was a devil's son, and she could not beskift him by no mean. And so on a time it happed that Merlin showed to her in a rock whereas was a great wonder, and wrought by enchantment, that went under a great stone. So by her subtle working she made Merlin to go under that stone to let her wit of the marvels there; but she wrought so there for him that he came never out for all the craft he could do. And so she departed and left Merlin.