Morgan ap Owen, Estate Head Gardener, in his Journals from the mid Seventeenth century tells the tale of why Fey law, Queens’ Law, is binding on humans as well. (It is not binding on cats on either side of the Border, but that’s a story for another night as the fire gets low and the whiskey takes full effect.) He said that ‘The Fey had many realities, but only one one True Ruler: The Summer Queen, as The Winter King holds his title at her sufferance.’ And Queens’ Law, Morgan said, ‘was harsh but fair.’
A visitor, a young male from the Riverrun Estate, had noticed and fallen in, not love, but certainly more than mere lust with what he took to be a Fey woman of his own age. (She was in fact many centuries old but still considered a child.) He thought she liked him. She said she did and claimed sanctuary here. The Queen was not amused. She asked for and got both sent over The Border to her. Then she showed the male just how old his prospective mate was. And that he would soon just be but a toy to her to be discarded when he grew old. He was rightfully appalled. And rather frightened!
She applied Queens’ Law on both of them. The Fey ‘child’ was banned from crossing the Border ever again. And Her law is binding: crossing the Border would have meant death by her becoming mortal, stripped of her magic. She was merciful on him: she stripped him of his memories concerning all things Fey and placed a Binding on him to keep him any future knowledge of the Fey. No star-crossed lovers would they be longing across a Border they cannot cross.