Brothers Pedro (Ezequiel Rodriguez) and Jimmy (Demian Salomon) discover that a “rotten” has been growing or decomposing or I don’t even know how to describe it in a nearby farmhouse when livestock start acting funny. That’s usually the first sign that things are about to go very wrong in any movie like “When Evil Lurks.” Keep an eye on the animals—they know before the humans do.
A “rotten” is a word for a possessed being, and it’s an appropriately descriptive term. In this case, the poor possessed soul looks like a bloated, oozing mess. But the human instinct to show this hideous abomination the end of a shotgun is the wrong one. That’s exactly what the demon wants because it unleashes the evil to do more harm. Well, of course, things go very wrong after some truly stupid decisions, and Pedro and Jimmy end up having to try and put the demon genie back the bottle as it creates grizzly havoc across their community.
And I mean grizzly. The first truly “whoa” scene involves an axe and a pregnant woman. And it gets gnarlier from there. In an era of cynical, meta horror, it’s refreshing to see something with a main purpose that isn’t so much “conversation starter” but “stomach turner.” Rugna builds tension through these extreme acts of abject horror, portraying an evil that can make humans and creatures act in the most unexpectedly violent manner, possessed by pure malevolence. The possession aspect of “When Evil Lurks” adds another layer to the tension in that no one can be trusted. It almost makes one wonder if Rugna’s film could be read as a COVID allegory in that once pure evil is unleashed, anyone can be infected and no one can be trusted.
Sadly, the stellar first half of “When Evil Lurks” is stronger than the second, in which Rugna has a tendency to overexplain what the brothers have to do and the general lore around a “rotten.” They even join forces with a “cleaner” (Silvina Sabater) who feels almost like a narrator to make sure the audience can follow what needs to happen next. It doesn’t help that the final act of “When Evil Lurks” ends up hinging on a largely silent autistic young man’s ability to withstand possession because demons can’t easily “figure out their minds,” a choice that makes Pedro’s son (Emilio Vodanovich) a pretty manipulative character.