Question: The 70th Cannes Film Festival took place from 17 to 28 May 2017, in Cannes, France featured what opening film, a 2017 French drama film directed by Arnaud Desplechin and starred Mathieu Amalric, Marion Cotillard, Charlotte Gainsbourg and Louis Garrel?
Sentence (from "Ismael's Ghosts"): The film follows a filmmaker whose life is sent into a tailspin, just as he is about to start shooting a new film, by the return of his wife, who disappeared 20 years ago and whom he thought dead.
Relevant evidence: No