Directed by Danny Philippou and Michael Philippou | Written by Danny Philippou and Bill Hinzman | 95 min | ▲▲▲▲△ | VOD

The filmmakers, two brothers from Australia, have credited many of their actors with “based on a concept by,” which speaks to the level of collaboration behind the camera. I’m not familiar with their process, but the film has an intimacy among its mostly young cast, which suggests a robust pre-production and rehearsal schedule. It’s paid off in this brutally grim and frequently scary horror movie from American indie studio, A24.

The concept is high, but the storytelling is gritty. We’re dropped into a slice of sweaty Adelaide youth culture, with Mia (Sophie Wilde) in its centre. She spends a lot of time at the home of friends since her mother died a couple years ago — Jade (Alexandra Jensen) and younger brother, Riley (Joe Bird), with mom, Sue (Miranda Otto), hilariously clued in to the likelihood of the teens bad behaviour.

One evening Jade heads to a gathering with her straight-edge boyfriend, Daniel (Otis Dhanji). She brings Riley and Mia with her, even though Mia has at least one frenemy on the scene. The kids indulge in a bizarre party game — one of them has a ceramic hand, said to contain the severed limb that once belonged to a medium.

Here’s how it’s done: Someone is tied down and a candle is lit. The restrained participant has to grasp the hand and say, “Talk to me.” They’re gifted with a vision of someone from the other side — ghost or demon, it’s not entirely clear. Then, with another verbal cue they’re temporarily possessed. It’s only safe to do this for 90 seconds or the “visitor” could become permanent — you’ve got to blow out that candle and pull away the hand to “close the door.”

I’ve heard dumber premises for both horror movies and games teenagers might play to scare their pants off, but it raises a lot of questions the movie isn’t answering: How did these rules get made and who made them? Where did the hand come from?

The scrappy, slightly confusing kitchen-sink drama of the opening act is a challenge to warm up to. We get a lot of characters in a short period of time and none of them terribly endearing — mostly just teen angst and acting out. Fortunately, things settle down and soon the stakes are solidly defined. A character is terribly hurt in their paranormal activity and may, in fact, be possessed by something horrible from the depths of hell.

Thematically, we’ve got two parallel threads here — the way the teens treat this supernatural nastiness like fun and games (haven’t they ever watched a horror movie before?) is a clear stand-in for hard drugs – meth, oxy, or any of an alphabet of party chemicals. When Riley begs to try it, the analogy is pretty clear. The second element is grief  — Mia’s absent mother and the shadow of the way she passed informs a lot of the horror here and Mia’s response to it. The film is clever in how it channels Mia’s perspective and the very real possibility mental illness may have skewed her view.

The darkness that overtakes this tale is relentless. As filmmakers, the Philippous know how to keep their audience guessing, have a solid visual style, and a knack for inspiring their actors to solid work. The rough edges in the opening, a few character notes that are introduced then forgotten, that’s pretty much nit-picking in a picture as wholly frightening as this one.