This is the true story of and (born Marie Régnault), two fascinating individuals whose colorful lives tragically intersect in Paris in 1887. , a determined woman with an independent mind, built a life and amassed a fortune for herself as the mistress of high-society men (and some women) in France. She witnessed some of the , including the protests of Républicains who rallied against Napoleon III's Empire at the funeral of journalist Victor Noir, the declaration of the radical Paris Commune, and the bombardment of Issy-les-Moulineaux. During a brief stay in Bavaria, she met King Ludwig II and composer Richard Wagner. A courtesan, a socialite, and a shrewd businesswoman, she climbed her way into the . But it all ended when she encountered Henri Pranzini. was born in Alexandria, Egypt. He had an , seductive eyes, and a brilliant mind. Knowing eight languages, he worked as a tour guide, an interpreter, a soldier, a trader, and an art dealer, among other things, but his true passions were . From attending the inauguration of the Suez Canal to serving in the British Army in Afghanistan and the Sudan, from Russia to Italy to Singapore, from Bombay to Burma, finally landing in France, a fastidiously dressed Pranzini was . This infamous dandy eventually spiraled into the orbit of the wealthy Régine de Montille. Crossing paths on the Champs-Élysées, their relationship culminated in a and a trial that rocked all of France. This , written in , is a , bringing to life two complex and captivating individuals and the incredible events of their lifetimes.