A shady business guy, Mark (Sam Neill), returns home to find that his wife Ann (Isabelle Adjani) is having an affair. He doesn't want to let her go and acts erratic but she insists she needs time to sort things out. The couple also have a young boy, who is mostly ignored. She says she has stopped seeing the guy but he doesn't quite believe her. So he confronts him and he insists he hasn't seen her in months. She begins to disappear for days at a time. Where is she going? Is she seeing someone else? Mark hires a detective to follow her but what he finds out is startling, to say the least. He tracks her to an old, dilapidated apartment where he encounters a strange, slimy, tentacled creature. But it's she who kills him. Then, things get even weirder...
This is an intense horror flick, with over-the-top performances. It's an unsettling premise of a woman having an affair with a THING. I've never seen another movie quite like it.