It was a nightmare, that's all.
If it's a nightmare, though, why is Ygraine meeting her in the hall with her belly round as the sun, saying the same breathless way she did in Nimueh's nightmare "It's time, I think. We'll love him, won't we? We'll do right by him?"
"All of us," Nimueh says. "All of us." Don't be silly, she said in the dream. You have nothing to worry about.
She ends the day screaming her grief and pain to the sky on the Isle, warning her fellow priestesses to run, just like she did in the nightmare. The vision.
She isn't dreaming. She's cursed, to live the last day of Ygraine's life and the beginning of Uther's mad revenge over and over again.
She kills herself while Ygraine screams her way through the labor.
She wakes up.
Before Ygraine can find her in the corridor in the morning, Nimueh leaves the palace and finds the dragons, the only ones who might know what's been done to her.
"Destiny is out of alignment," says the Great Dragon, with his usual impressive weight to the words. "We have seen the future as it stems from this day as you lived it, and it is unacceptable to us. Ygraine Pendragon must live."
"I can't control what sacrifice the magic takes."
He laughs. Infuriating beast. There's a reason she prefers to speak to the dragonlords and not the dragons. "Can you not, High Priestess?"
When she returns to the palace, Ygraine is already dead.
"I'm sorry, I'm sorry, I'm sorry," she tells Ygraine between contractions, weeping, kissing her palm, while Ygraine looks down at her in terror. "We never told you because you would say no, and the land needs your son, but there must be a sacrifice. A life for a life. I'll give my own."
Then it's Ygraine weeping, but Nimueh does everything she can to find the old magic, to trade her life for Ygraine's.
Nimueh wakes up.
"Did you think your death would please the Old Religion any more than that of Ygraine Pendragon?" the Great Dragon asks when she finds him again.
She kills Uther, and sees the glory of Ygraine alive after Arthur's birth, but regicide means she doesn't live out the day.
This time, she pushes him off the castle battlements, and makes sure no one sees.
It isn't enough of a sacrifice, that way.
"Please, Uther, I have had a vision from the Old Religion--the magic wants her life for the child's, and it won't take mine. We need an alternative. Give me an alternative. I cannot bear Ygraine's death, and you despise me, I know, but remember that you cannot bear it either." This Uther of the morning is a different creature to Uther after Ygraine's death. She has seen it in him like a candle blown out for more than what should have been a cycle of the moon now.
He frowns. "We will kill a prisoner."
"Their lives are not important enough." She wants him to offer himself, but she knows he won't, and even why he won't. A king isn't a monster for not wishing to leave a wife and an infant son to rule a kingdom. He's wise.
"I'll find someone."
He brings her Gaius, in the end.
Alice spits in her face before sunset.
It doesn't matter. Gaius, it seems, cannot provide her the necessary sacrifice either.
"Who can die?" she asks the Great Dragon in despair. "The child? Ygraine would not forgive me for giving her a child and then taking it from her. Another priestess? They all called it folly when I took the power of life and death, they wouldn't save me from it."
"You will find the answer."
"Do you wish to live this day for countless centuries?"
Nimueh wants nothing more than to wake up somewhere warm and happy, to wake and visit Ygraine and her bawling brawny son in her chambers. "Then tell me who must die."
"I was not the one who took the power of life and death in my hands."
"But you say the child is needed. I couldn't have done anything else."
He just laughs. "There's the riddle, then."
She finds herself watching little Morgana, who Uther dotes on just a little too much for the child of his dearest friend, but she cannot bear that. Nimueh won't become a monster. Not that much of one.
A High Priestess has a few tricks under her sleeve. Nimueh packs the right knife and the right spell in one of her bags and goes back to the Great Dragon.
"I had wondered if it would come to this," he says, as smug as ever.
"Is it the answer?"
"I suppose, young priestess, we will find out in the morning."
"Will your kin kill me for this?"
"I doubt it. Even the dragonlords know that something has unsettled us. Speak to Balinor. He may understand. Though you may wish to avoid these lands for a while, if time continues."
"Your sacrifice is appreciated."
From the shadows, it's nearly time. Ygraine must be bearing her son, wondering where Nimueh is, while Uther paces the throne room like a caged bear (she paced with him a few times, pretended when the news came that she thought it was merely any death in childbirth, but Ygraine's death will always mean the beginning of Uther's vendetta, it seems).
"Make him a worthy king," says the Great Dragon.
Nimueh walks away from the dragonlands to the sounds of keening, the dragons mourning their own, but none of them tries to prevent her departure. He's lived his centuries upon centuries. He might have lived fifty years more, but perhaps not even that much. Nimueh doesn't feel much guilt for depriving him of life.
She doesn't whisk her way back to the palace to see the newborn prince. Instead, she stays on her own in the forest, so she has no news at all of whether mother and son made it through the day alive.
Nimueh wakes in the forest instead of the palace and laughs at the sky before she starts her way home.
"Where did you go?" Ygraine asks, exasperated, when Nimueh comes to visit her room. Arthur is a little handsomer on his second day, less red and squished, asleep on his mother's breast. "You tell me you'll be here to meet my heir and then you disappear on the day of his birth."
Nimueh kisses her hair and strokes Arthur's cheek. He's a fine strong boy. They'll raise him into a good king, she and Ygraine. Even Uther and Gaius. "I had an errand. Unavoidable, I'm afraid. But it's good to see you both well."