The narrative is either based on historical facts, or departs from them, rushing towards a different reality. Everything moves and turns in this dizzying book. But the apparent arbitrariness is subject to immutable, albeit unusual, laws. And the terrible life stories of Beatrice Cenci, the Marquise de Brenvilliers and Augusta Fulham illustrate the words of Shakespeare: “Lord, we know what we are, but we know not what we can become.”