Geneviève is a skinny, precocious girl with a mind full of philosophy and the remarkable power to read the swirling waters of an oracle glass. Left for dead by her family, she is taken in by the ingenious occultist La Voisin, who rules a secret society of witches that manipulates the rich and the scandalous all the way up to the throne. Tutored by La Voisin, Geneviève creates a new identity for herself - as the mysterious Madame de Morville, rumored to be one hundred fifty years old. Soon, even the reigning mistress of the Sun King himself consults Madame de Morville on what the future holds for her. And as Madame de Morville, Geneviève can revel in what women are usually denied - power, an independent income, and the opportunity to speak her mind. But beneath her intelligence and wit, and in the face of unexpected love, Geneviève is driven by the obsessed spirit of revenge.