Faced with Regan, a delicate 12-year-old girl who terrifyingly takes on other people's likenesses and voices, doctors claim there is nothing to be done. When people around her begin to die, the mother realizes that her daughter is possessed by the devil. The only possible hope appears tied to two priests and the ancient rite of exorcism against the devil.

William Friedkin born in Chicago in 1935, died in Los Angeles in August 2023.

At a very young age he decided to dedicate himself to directing. Hired at 17 as a delivery boy for television in Chicago, he began directing live broadcasts and then documentaries. In 1965, he directed one of the last episodes of the series Alfred Hitchcock Presents. He then made his first feature film, Good Times, in 1967. The Thieves of the Law (1971) and The Exorcist (1973) established him as a prodigy of the New Hollywood and a profound innovator of detective films and horror. Both films enjoyed enormous success with the public and won numerous Oscars. This was followed by The Wages of Fear, a remake by Henri-Georges Clouzot, Cruising, with Al Pacino, in 1980 and To Live and Die in Los Angeles (1985). In 2006, Bug, a mental dive into madness and destruction, caused a sensation at the Directors' Fortnight. Killer Joe (2011) earned him the Golden Lion for Lifetime Achievement at the Venice Film Festival. The Caine Mutiny Court-Martial (2023) is his last film, posthumously.