This work is the first to analyze Marguerite Yourcenar’s fictional manuscripts collected by the Houghton Library at Harvard University. Béatrice Ness organizes her study into five main groups of manuscripts spanning from 1924 to 1987, the year of Yourcenar’s death. Ness’s genetic approach problematizes questions of truthfulness and falsity: Yourcenar directs the reader’s interpretation of her work by selecting and arranging diary notes, correspondences, and manuscripts of novels. As a result, the critic must undertake a careful reading of Yourcenar’s 'avant-textes' to answer the questions: what does the manuscript reveal and why are these specific documents accessible to the public? Ness shows that Yourcenar tries to assure a posthumous reading that validates the originality of some aspects of her writing process, such as the aesthetic appeal of the drawings in her manuscripts, her mobility while she writes, and graphic transformations of penmanship revealing metempsychosis. Yourcenar’s clever practice calls for an inventive reader to transcribe a filtered reality.