Fungus/mould in basement horror film
I’ve been trying to remember this movie for years and it’s driving me insane. I watched it on TV a long time ago, probably sometime in the 2000s, but I think the movie itself was either late 90s or early 00s. It might be a straight to vhs or dvd movie.
What I remember:
-The main characters are a husband and wife, and I’m pretty sure they’re both scientists or researchers. They also work with a small research team. There is a lab as well. They might be working for a pharmaceutical company.
-They either move into a new house or are already living in one where they discover some kind of strange mould/fungus/slime growth. I strongly remember it being connected to the basement, and I think it slowly spreads through the house. The woman even has some nightmares or hallucinations about it at one point.
-Once they find the mould they start experimenting with it in the lab. At first the fungus seems beneficial, it makes people feel energized, hyper-focused, maybe euphoric or mentally sharper.
-Now this part gets blurry. I think that the husband starts using it and then he increases the dose, and maybe other researchers do too. Eventually it turns out to be toxic/poisonous and he dies from it (or mutates before dying? not fully sure).
-The whole movie had a very strong haunted house atmosphere: dark interiors, damp walls, creeping dread, isolation. But I don’t think there were actual ghosts or supernatural hauntings. The horror came more from the organism itself and the atmosphere. It wasn’t a grand mansion or big old house either, if I remember correctly.
-It was not a fast-paced action horror movie from what I remember, it only picks up pace towards the end when the guy dies.
Does this ring a bell for anyone? I’m starting to feel like I had some mould myself because this is like a fever dream, yet some images I feel like I remember vividly.