Jim Henderson (Christopher Plummer) is a Montreal detective who has just been called out to this apartment block in the dead of night. Seems a taxi driver watched a young woman fall to her death from the top of the building, but she might not have been a suicide: she might have been murdered. He interviews the taxi driver then goes back to look at the body, whereupon his partner, Paquette (Donald Pilon), realises that he recognises the deceased. She was a prostitute around this area, and he knows who she associated with, so at least they have a few leads to try out...
Harvey Hart was a Canadian director who mainly worked in television, but he did make a few big screen efforts, and The Pyx was one of them. This too was Canadian, and made sure we knew it by having characters conduct conversations in both English and French, none of it subtitled so you had to rely on your knowledge of one or the other, or both, if you were bilingual, to work out what was going on. Certainly this was truer in the early scenes than those later on, as after a while the film settled on English as the language to stick with, but it made a murky plot come across as all the more impentrable, in the opening stages at any rate.
Nowadays, if you've heard of this at all it's because you know it to be a horror film, probably put into production on the strength of the box office business that Rosemary's Baby did, as there were quite a few Satanic-themed chillers released in the early seventies that looked to that film's unease with modern life as a jumping off point. But actually The Pyx doesn't let on that this is its subject matter until quite late on in the story, so you are aware the dead woman was involved with something shady, but to all intents and purposes you're watching a police procedural not anything with devil-worshipping cults roaming the then-modern Montreal: the sole clue is what Henderson found on the body.
Black fares a little better in keeping us enlightened as to Elizabeth's misery, as we see she was a heroin addict as well as a whore, and she was not really blessed with too many friends; indeed, after a while following the detective we see those acquaintances she did have being bumped off by mysterious agents, something which should have increased the paranoia quotient but actually makes this come across as even more dejected. It's as if the whole movie has suffered a crisis of faith, encouraging it to wonder what the point of going on is, just as Elizabeth does when she agrees to participate in the Satanic black mass that proved so fateful to her (and not only because it sounds as if The Smurfs were attending, bizarrely). There's so little cheer in The Pyx that it's hard to recommend unless your taste gravitates towards real downers; Black's singing of her own Joni Mitchell-esque songs on the soundtrack doesn't alleviate the gloom either. Music by Harry Freedman.