Produced and filmed over seven years (between 1984 and 1991)
Most of the film was shot on 8mm film. For moving shots, the 8mm was taped to an old wheelchair as a makeshift dolly. Later in production, when the filmmakers came by some money, they shot on 16mm and rented a boom (notably the opening sequence with the two girls being chased in the Laurentians by the cult members and all subsequent related scenes).
The graveyard scenes were filmed without permission. The crew drove in and set up a bed on someone's grave site and began rolling. When the grounds keeper approached them, they fled with the bed. When they reached their car, which had been left with the window rolled down, they realized their earlier reel was missing. The grounds keeper had taken it because he wasn't sure what was going on. Luckily for the filmmakers, it was returned to them.
"Differences" with the director led to lead actress, Micheline Richard (Tracy), leaving mid-production. Maurice Devereaux was forced to film the rest of the film with a double. These scenes are shot from afar so that you can't see her face clearly.
The film was not overdubbed to hide the actors' French Canadian accents as reported on some sites. Most of the film was done without sound (save for the crisper-looking scenes set in the past), or script supervisor. Maurice Devereaux did not think to write down slight deviations from the script by the actors, so when it came time to overdub the sound, they had to guess as best they could what to say. This is one of the reasons the sound is not well synced.