The inimitable Nancy Mitfordâ€™s account of Voltaireâ€™s fifteen-year relationship with the Marquise du ChĂ˘teletâ€”the renowned mathematician who introduced Isaac Newtonâ€™s revolutionary new physics to Franceâ€”is a spirited romp in the company of two extraordinary individuals as well as an erudite and gossipy guide to French high society during the Enlightenment. Mitfordâ€™s story is as delicious as it is complicated. The marquise was in love with another mathematician, Maupertuis, while she had an unexpected rival for Voltaireâ€™s affections in the future Frederick the Great of Prussia (and later in the philosopheâ€™s own niece). There was, at least, no jealous husband to contend with: the Marquis du ChĂ˘telet, Mitford assures us, behaved perfectly. The beau monde of Paris was, however, distraught at the idea of the loversâ€™ brilliant conversation going to waste on the windswept hills of Champagne, site of the ChĂ˘teau de Cirey, where experimental laboratories, a darkroom, and a library of more than twenty-one thousand volumes enabled them to pursue their amours philosophiques. From time to time the threat of impending arrest would send Voltaire scurrying across the border into Holland, but his irrepressible charmâ€”and the interventions of powerful friendsâ€”always made it possible for him resume his studies with the cherished marquise.