In 1878, the author Marius Roux, a noted friend of Emile Zola and Paul Cézanne, published La proie et l'ombre, a little-known roman à clef featuring a thinly disguised Cézanne as the main character, Germain Rambert. The text prominently features several conversations drawn from famous Impressionist discussions on the nature of art. La proie et l'ombre offers a unique insight into the thoughts and lives of the Impressionists. Cézanne scholar Paul Smith has resurrected this all-but-forgotten novel, recognizing its value in expanding our understanding of the Impressionists' world in general and Cézanne's in particular.

This translation, titled The Substance and the Shadow, also brings to the foreground the effects of a burgeoning capitalist economy on the artistic practices of the period. With changes in the Salon and the dealer system, art in France was no longer reserved for the privileged few, and artists increasingly found themselves attempting to appeal to the merchant classes. Art had become a commercial endeavor in ways never before imagined, and the story details Rambert's—and, by extension, Cézanne's—attempts to cope with the shift.

In a substantial introductory essay, Paul Smith discusses the nature of the roman à clef and its use as a historical document, and provides an examination of the relationship between Roux's characters and their real-life counterparts.