What do famous people talk about behind closed doors? That question is only interesting for about two minutes. But wondering what legends talk about behind closed doors? You can build a whole movie around that, as Regina King does with her directorial debut One Night in Miami, its screenplay adapted by Kemp Powers from his play of the same name. On February 25, 1964, Malcolm X, Sam Cooke, Jim Brown and Muhammad Ali—at the time still going by the name Cassius Clay—gathered in a hotel room in Miami to celebrate Clay’s audacious victory over Sonny Liston earlier that evening.