If you ask any horror movie buff about the films that they think defined the genre, you'll almost always hear the same suggestion come up: The Exorcist.
The 1973 film - which follows the story of 12-year-old Regan who becomes possessed by a demonic entity - shocked and terrified audiences when it was first released, and continues to do so today.
Before the film, however, there was a book of the same name, and before the book, there was the "real" story that inspired it all.
It all started in 1949, when a 13-year-old boy known only as 'Ronald' began to experience things that could only be described as supernatural. He had recently suffered the loss of his aunt, a spiritualist, and was reportedly pretty torn up over it.
As well as going through the normal effects of grief, however, Ronald also heard strange scratching sounds coming from his room, witnessed water dripping from the walls, and would frequently be jolted about when his mattress moved without explanation.
Similar to the plot of The Exorcist, Ronald's family sought help for the young boy's disturbances. They turned to doctors, psychiatrists, and their local Lutheran minister, but nobody could provide an explanation for what was happening to the teen.
In February of 1949, Ronald's family turned to desperate measures, and organised an exorcism.
It was performed by Father E. Albert Hughes - a Catholic priest. Unfortunately, it didn't go well, as Ronald managed to remove a spring from his mattress (despite being tied down to the bed) and cut the priest across his shoulders.
Just days later, the word 'Louis' appeared on the boy in red scratches, which his family took as a sign that they should proceed to search for help in St. Louis, where they had some family.
Once there, they got in touch with Father Walter H. Halloran and Reverend William Bowdern, two Jesuit priests who performed a second exorcism in early March of 1949. During the process, they claim to have witnessed the mattress moving, as well as scratches appearing on Ronald's body.
What's more, there are reports that the 13-year-old would enter a "trance-like state" at times, and had been heard saying things in an unfamiliar, guttural voice. Again, as the 1973 film portrayed, Ronald would also react violently in the presence of a "sacred object", and could even cause objects to fly around the room.
This reportedly went on for months, with several incidents seeing Ronald urinating on himself, cursing at priests, and even suffering seizures. When it became unmanageable, the boy's parents sent him to Alexian Brothers Hospital in St. Louis. It was there, at last, that a "miracle" occurred.
On Easter Monday, 1949, a group of priests conducted one last exorcism that lasted for a full seven minutes. It was a terrifying and violent ordeal but, at the end of it, Ronald apparently sat up calmly and said: "he's gone."
The true identity of Ronald is not known, and the story is often recounted with the pseudonyms like "Roland Doe" or "Robbie Mannheim". It is believed that the boy could possibly have been Ronald Hunkeler, but nobody can say for sure.
By all reports, whoever he was, Ronald went on to live a normal life. The demons never bothered him again, and his actions (unlike those of the demon possessing Regan in The Exorcist) never killed anyone.
It may sound unbelievable, or perhaps even unremarkable, to some, but that's what makes this story more terrifying than the book or the movie. A lot of people - religious people who swear by God - claim that this took place, but we may never fully know the truth about what happened.
