Few films have left as indelible a mark on the horror genre as The Exorcist. Released in 1973 and directed by William Friedkin, it remains one of the most terrifying cinematic experiences ever created. Based on William Peter Blatty’s novel, which itself was inspired by a real-life exorcism of a 13-year-old boy in Maryland, the film shocked audiences with its visceral depiction of demonic possession and spiritual warfare. But what happened behind the scenes was arguably even more chilling. 

Lisa Cannon tells us all about this Halloween horror.