In a remote cabin nestled deep within the forest, researcher Dr. Emily Carter discovers an ancient manuscript that speaks of a cursed bodily function - a demonic possession that transforms human waste into a sentient, malevolent entity. As she translates the text, strange occurrences plague the cabin: toilets overflow with an otherworldly black substance, and a foul stench permeates every corner. Dr. Carter dismisses these events as plumbing issues until she witnesses the impossible - her own excrement crawling back out of the toilet.
The horror escalates when Emily's research assistant goes missing, only to be found days later covered in a thick, putrid sludge, babbling about "the waste that watches." The local townspeople warn Emily about a centuries-old curse that strikes when certain forbidden knowledge is unearthed. As more people disappear, Emily realizes a terrible truth: the manuscript wasn't documenting the curse - it was containing it. Her translation has unleashed an ancient entity that uses human waste as both portal and vessel, turning the most private bodily function into a gateway for unspeakable terror.
Emily desperately searches for a way to reverse the curse as the entity grows stronger with each victim. The possessed waste begins to coalesce into humanoid forms, hunting down the living to force-feed them substances that accelerate the reproduction of the parasitic presence within. With time running out and the entity spreading beyond the forest, Emily must confront the source of the horror in the most intimate way possible - by allowing herself to become a vessel for the curse so she can destroy it from within, risking her humanity in a battle against the most degrading possession imaginable.