In her heart of hearts, Charlotte was a knife. Almost everyone in Paris called her Madame Guillotine. Louis simply called her Charlotte. From the very beginning, they shared a singular intimacy, a tenderness that was theirs alone. Madame Guillotine had many lovers over the years, but she always came back to Louis. Six days a week she stood tall and proud in the square, kissing her lovers’ necks. But on those days, the one that her edge longed for was Louis. Every Monday, she gave herself over to his methodical devotion, relaxed in his hands and let his callused fingertips polish her edge.

Louis, a tinker by trade and a Romany by birth, spent much of his life traveling from town to town, repairing tools and sharpening anything with a blade, just as his father had before him. It was the only life he knew, and he was proud of…