The Ninth Configuration (also known as Twinkle, Twinkle, "Killer" Kane) is a 1980 American film directed by William Peter Blatty. The film is based on Blatty's novel The Ninth Configuration (1978), which was itself a reworking of an earlier version of the novel, first published in 1966 as Twinkle, Twinkle, "Killer" Kane!. The initial 1966 publication of the novel featured an exclamation mark at the end of the title, while all subsequent publications saw it removed.