She turns her glance from the river to me, her pupils darkly dilated. “Do you remember now? As we sit here by the river? The very same river?”

I nod.

“We said: ‘Our boy was taken when he was not yet a man, not yet king—though he was born to be both. So take his murderer’s son while he is yet a boy, before he is a man, before he comes to his estate. And then take his grandson too and when you take him, we will know by these deaths that this is the working of our curse and this is payment for the loss of our son.’ ”

I give a shiver at the trance my mother is weaving around us as her quiet words fall on the river like rain. “We cursed his son and his grandson.”

“He deserves it. And when his son and his grandson die and he has nothing left but girls, then we will know him for the murderer of our boy, Melusina’s boy, and we will have had our revenge.”

“That was an awful thing that we did,” I say uncertainly. “A terrible curse on the innocent heirs. A terrible thing to wish the death of two innocent boys.”

“Yes,” my mother agrees calmly. “It was. And we did it because someone did it to us. And that someone will know my pain when his son dies, and when his grandson dies and he has no one but a girl left to inherit.”

People have always whispered that my mother practices witchcraft, and indeed her own mother was tried and found guilty of the dark arts. Only she knows how much she believes, only she knows what she can do. When I was a girl, I saw her call up a storm of rain, and I watched the river rise that washed away the Duke of Buckingham’s army and his rebellion with it. I thought then that she had done it all with a whistle. She told me of a mist which she breathed out one cold night which hid my father’s army, shrouding it so that he thundered out of a cloud on the hilltop and caught his enemy by surprise and destroyed them with sword and storm.

People believe that she has unearthly powers because her mother came from the royal house of Burgundy, and they can trace their ancestry back to the water witch Melusina. Certainly we can hear Melusina singing when one of her children dies. I have heard her myself, and it’s a sound I won’t forget. It was a cool, soft call, night after night, and then my brother was not playing on Tower Green anymore, his pale face was gone from the window, and we mourned for him as a dead boy.

What powers my mother has, and what luck runs her way that she claims as her doing, is unknown, perhaps even to her. Certainly she takes her good luck and calls it magic. When I was a girl, I thought her an enchanted being with the power to summon the rivers of England; but now, as I look at the defeat of our family, the loss of her son, and the mess we are in, I think that if she does conjure magic, then she can’t do it very well.