Note: This article contains spoilers for Joker.
Joker star Zazie Beetz has shared her theory on the film, and it potentially changes everything about the way the story is told.
Beetz, who portrays a neighbour of Joaquin Phoenixâ€™s Arthur Fleck, toldÂ The Hollywood ReporterÂ that almost everything depicted in the movie could simply be a figment of Fleckâ€™s imagination.
She said: â€œI think that the entire film is all through Arthurâ€™s point of view, almost the entire thing, so, to an extent, you can question the interpretation of anything in this film.â€
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Joker flirts with the notion of whatâ€™s real and what isnâ€™t throughout its running time, and Beetzâ€™s character, Sophie, is at the centre of that.
Fleck imagines an entire relationship with her, based on a single conversation they have while sharing the lift up to their respective apartments.
But her characterâ€™s specific role is not the only thing that Deadpool 2 star Beetz believes could be taking place inside the protagonistâ€™s head.
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â€œI think the movie just really shifted into something where itâ€™s all coming from his brain,â€ she said.
â€œIn the end, isnâ€™t it all up for questioning? What is reality or what isnâ€™t reality as he questions his own reality and his own existence in the world?â€
Despite controversy prior to its release, Joker is already a bona fide success at the box office,Â breaking the all-time October opening recordÂ â€” set last year by Venom â€” with its $93.5m (Â£76m) domestic debut.
The film won the Venice Film Festivalâ€™s top prize, the Golden Lion, and is being talked about as a major Oscar contender, withÂ sequel ideasÂ inevitably swirling as well.
Director Todd Phillips, who was previously best known as the man behind the Hangover trilogy, hasÂ shut down rumours of a sequel, saying there is â€œno planâ€ for a follow-up movie.