What is the importance of the Sheppard manuscript in the book, Confessions of the Fox?

The manuscript, the narrative of which makes up the book's main narrative, represents secret truths that are finally revealed. There are several facets to this symbol, perhaps most importantly the secret truth it professes to reveal at the core of the lives of its characters, which are in turn evocations of what are presented as secret truths about race and gender that have been hidden within history. On another level, the manuscript itself, as portrayed in Voth's footnote narrative, has been kept secret and/or hidden for years. On yet another level, his discovery of, and work with, the manuscript triggers him to consider and examine truths about himself, his relationship with his ex, and his relationship with his work.