At the beginning of F For for Fake, Orson Welles’ 1973 essay film about forgery, deception and lies, the filmmaker addresses the audience directly and sets out a thesis for what is to follow. ‘Tell it by the fireside or in a marketplace or in a movie,’ he says, ‘almost any story is almost certainly some kind of lie.’ He promises that, over the course of the next hour, he’s going to give them the unvarnished truth.

David Fincher’s Mank is based on one Hollywood’s most discredited fictions: the idea that screenwriter Herman Mankiewicz was the real genius behind Citizen Kane and that Welles’ screenwriting credit and the Oscar that resulted from it were unearned. Mankiewicz (Gary Oldman) sums up the argument at the end of the film when, having skipped the Oscars ceremony, he addresses the press. ‘I am very happy to accept this award in the manner in which the screenplay was written,’ he says, ‘which is to say in the absence of Orson Welles.’