Welcome to the special Halloween episode of Unexplained, with me, Richard McLean, Smith.

From the cap stepped a tall old man, black raincoat and hat, and a battered valise. He

paid the driver, then turned and stood motionless, staring at the house. The cap

pulled away and rounded the corner of 3060 Street. Kingdomman quickly pulled out

to follow. As he turned the corner, he noticed that the tall old man hadn't

moved, but was standing under the street like glow in the mist, like a melancholy

traveler frozen in time. And so marks the arrival of the eponymous exorcist in

William Peter Blattie's extraordinary novel, first published in 1971. The scene was

later immortalised as the poster of the film adaptation. Released on December 26,

1973, it is for many the most iconic horror film of all time. From William

Friedkin's masterful direction, to Blattie's profound and personal script, to the

intensely evocative use of Mike Oldfield's tubular bells, it is a cinematic

masterpiece. It is also regularly described as the scariest film of all time, that on

first screening had audience members fainting and vomiting in the aisles, with many

reduced to tears by the sheer terror of it all. Ambulances and paramedics were

regularly dispatched to attend to the hapless viewers. But what many people don't

know is that Blattie's Nightmarish book was in fact based on a real life

exorcism. This is that story.

The town of Cottage City, in Maryland, stretching from the Fortling Confusional home to the

banks of the Anacostia River, is today home to a small but proud working-class community

of roughly 1200 inhabitants. Back in the early 1900s, alongside what is now Colmar

Manor, the area was the place to settle irreconcilable differences. Between 1808 and 1868,

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