“Oh, God!” said Sir Yvain; “what a great pity when such good knights as they were are so bewitched and shamed by magic. Never, anywhere I’ve ever been, have I heard of such a marvel: that one could thus by necromancy or enchantment take a man’s mind from him.”

“Yet one can,” said the knight; “that you may now clearly see.”

“It’s too bad,” he said, “and a great sorrow, for these worthy men are shamed by it, and many others will lose by it, and many maidens will be shamed and besmirched because of it, as soon as those at court know that we’ve lost them thus by the machinations of young ladies. Nevertheless, do you think they can be taken away from here either by prowess or by any chivalric deed a man can do? For I swear to you that, if King Arthur knew now that they were here, he wouldn’t stop
until he had laid siege to this rock and had it taken, using picks and other sharp weapons.”

“If he wanted to meddle in this,” said the knight, “it would be wasted effort, for if this maiden now saw this rock besieged, she would use her magic to make the greatest flood in this country flow past the rock, so that, if you were up there or nearby, you’d see nothing but water for as long as she wished.”

“By my faith,” said Sir Yvain, “thus she could shame the whole world, if she wished.”

“Indeed,” said the knight, “she could harm many a noble man, if she wished, but she does not wish to, for there are many things she doesn’t do, lest she sin.”

Post-Vulgate Merlin