Mixing fact with fiction, Danièle Thompson (very) loosely retells the complex friendship of Emile Zola and Paul Cézanne in Cézanne et Moi, especially how Cezanne helped Zola see from a painter’s point of view.
Though they were childhood friends in Aix and later in Paris as young men, their friendship eventually stuttered and stalled. Thompson’s picnic (a probable fiction) in Aix is held during a momentarily happy phase and meant to show their camaraderie in the stunningly beautiful landscape of Province. 
Zola, his wife Alexandrine, Cézanne with his mistress Hortense, and other friends chat, eat roast chicken and bread, and drink wine. It’s all smiling here and now, momentarily. Soon, their contrary personalities and Zola’s success cools the friendship. Cezanne was displeased by Zola’s preference for Manet, whom he considered the superior artist. Without corroboration, Thompson accepts that Cézanne was angry at Zola’s portrayal of a failed artist in his novel L’oeuvre (The Masterpiece); more likely, it was the painter in Madeleine Ferat.
Thompson glosses over Cézanne’s sexual ambiguity and his shyness with women. She’s also not inclined to have Zola and Cezanne discuss their positions about the Dreyfus affair that polarized France because of its anti-Semitism. Zola passionately defended Dreyfus while Cezanne was an anti-Dryfusard.
The cast: Guillaume Canet as Emile Zola; Déborah Francois as Hortense Cézanne; Guillaume Gallienne as Cezanne; Alice Pol as Alexandrine Zola
See Daniele Thompson. Cézanne et Moi (2017). Screenplay is by Danièle Thompson.