You hate to be racist against Britons and put all their efforts in the same box, but it's tough to not think about Hammer when you're watching The Asphyx. It's not just the accents—this is a period piece about relationships torn asunder by a man's Frankenstein-like transgressions of science. Hugo Cunningham is a rich philanthropist with a penchant for photography. He accidentally discovers that he can capture some thing floating near people as they're on the brink of death.
This is the asphyx of the title, which Greek mythology describes as a spirit of death which arrives to take your soul at the end of your mortal story. Cunningham crafts a bunch of Ghostbusters-style tech to imprison the asphyx, believing that this will lead to the subject's immortality.
Because PETA wasn't around in the 1800s, these products are tested on animals. Awww, look at the little guinea pig's asphyx, soooo cuuuute! Since this is a horror film, things go as awry as you'd expect. The structure of the film has a ton in common with Hammer Studios' better entries: tension is slowly erected and the horror is often delivered via implication rather than GORE SHOT BLERGH.
It's a calm, eerie, and pretty original film. The unwieldy central conceit could have been laughable if the cast & crew didn't take things so seriously. Luckily for us, they did. And the performances are generally energetic and powerful, and the shots and camerawork are rendered with solicitous care, and the movie is a better and stronger thing for it. I rolled my eyes hard during one of the early scenes, where the dialogue was overlaid with this 70s AM-gold music, but that appears to have been a weird one-off. Otherwise, The Asphyx is all about serious business.
It feels like a throwback when measured against contemporaries like Last House on the Left and The Exorcist, but the old-school charms of The Asphyx are well worth your time.