So Merlin stayed with Ninianne and lived there night and day, and he loved her so passionately that he loved nothing else in the world so much. Because of the great love he had for her, he did not dare ask her to do anything for him, for he dared not anger her. He kept thinking that in some way it would happen that he could have his will with her completely.

He had already taught so much magic and necromancy to her that she alone knew more of it than anyone but Merlin, and no one could think of a good entertainment or game that she would not make by enchantment. But there was nobody in the world she hated so mortally as she did Merlin, because she knew well that he desired her maidenhead; and if she had dared to kill him, either by poison or in some other way, she would have undertaken it boldly, but she dared not, for she feared that he would know about it, since he was wiser than other men. Nevertheless, she had already so enchanted him by the very magic she had learned from him that she could say whatever she wanted before he knew a thing about it.

[...]

“Indeed,” said Merlin, “I’m staying away from Great Britain for two reasons: one is my love for you, for I love you so much that I couldn’t live without you; the other reason I stay away is that my divination tells me that as soon as I get there, someone will kill me, either by poison or in some other way.”

“What!” she said, “and can’t you protect yourself?”

“No,” he said, “for I am already so much under the spell that I don’t know who is preparing this death for me.”

“You have known such a large part of events to  come,” she said, “and yet are you now brought to this because you have lost the art?”

“I still know a great deal of what does not pertain to my life or death,” he said. “But in my own concerns, I am so opposed by spells that I don’t know how to help myself, for I cannot unmake the enchantments that are made unless I want to lose my soul, but certainly, I would rather my body were given over to death through treason than that my soul were lost.”

At this news the maiden was glad, for she longed for nothing so much as Merlin’s death, and he could know nothing of what she said or did, for she was too well armed against him by necromancy.

Post-Vulgate Merlin