Describe it? I can't do that. I wasn't there, would not be anywhere for some seasons yet, in the very nature of things.
But I can reconstruct it.
I've known the way it went since long before I understood it, could tell it almost from the time I could speak. I know the facts, and I can guess the truth.
It's spring in Caerleon.
She's young -- though not as young as he is; still in the first full flower of her dark beauty. Beside the hard calm of her sister, she makes you think of storms, of the sea rather than the lake. Everyone remarks it. The men remark it particularly.
She will be married soon; it's only a matter of time.
No one's asked her what she thinks about it. She's never expected to be asked, but that doesn't matter, doesn't change the rebellion in her heart. She's just beginning to realize how much she wants and how much she's capable of. She wants more than her mother's life, tossed like a trinket from one man's possession to another. She wants more than her sister's life, turned (no one's told her otherwise) from study, from knowledge, to the straightforward production of children.
She wants power. She wants choice.
Don't mistake her: she chooses.
With her eyes open, she chooses him. He's their darling, their hero, their heaven-sent prodigy. At this moment he can do no wrong.
He's her mother's son, but they don't know that, he won't know that, until it's far too late.
For their paths cross in Caerleon, and the boy is handsome like his father who is not her father, and she is beautiful and angry, with the kind of anger that drives men to bloodshed. She takes it out on him. He lets her do it. It's not her last cruelty, and not the last time he will fail to see what he should.
If it had happened another way -- if they had both been innocent, or both remorseful, or both defiant -- the result might have been different. There might not even have been one; she was deep in herb-lore even then. Instead there was me.