Tarantino explained in interviews only after the film was released that the very earliest concept of what became this story was a sequel to Django Unchained he began as a novel called 'Django in White Hell.' However, he did not get far with the novel before he realized that it didn't work to have a character who's morals were known to the audience beforehand, nor a character you felt was fairly sure to survive. Tarantino withheld this trivia from interviews until after the film's release because he was already contesting false reports that the movie would be a sequel to Django Unchained and didn't want to further muddle early public expectations. This is also why, in the wake of the script's leaking online, he was considering taking the story back to novel form when he considered canceling production.