By the time of her sudden death in 1996, X had achieved worldwide celebrity for her tireless transformations and the mystique they sustained. But one role remained unknown to the public: That of the wife to a largely ordinary woman named C.M. “Biography of X” is framed as Lucca’s book, written partly to correct the errors of unauthorized biography but mostly in an anguished effort to uncover the secrets of a woman with whom she was so intimate yet knew not at all. As the chapters recount Lucca’s interviews with the people whom X, under different guises, knew, loved and exploited through the decades, it describes a strangely mutated version of American history as well. The imagined details of the Great Disunion, as it’s called, yo-yo between the plausible and the preposterous (FDR chief-of-staff Emma Goldman?

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