After the astonishing success of 1973’s The Exorcist —which won over critics, the Academy, and audiences alike, and is still considered one of the greatest horror movies ever made—the studio decided it wanted a sequel. In 1977, The Exorcist II: The Heretic hit theaters. It is still considered “one of the most famous failures of all time in the cinema,” to quote its director, John Boorman.

New documentary Boorman and the Devil , directed by David Kittredge ( Queer for Fear ) , interviews Boorman and many others in its fascinating excavation of what went wrong. The short answer is “nearly everything,” and the end result is a step-by-step cautionary tale of what not to do, as well as an insider’s peek into a Hollywood that barely resembles its current incarnation.

© Yellow Veil Pictures

These days, planning for a sequel after a hugely popular blockbuster would be an automatic next move. Obsession 2 talk started not long after the first film dropped.…