I try to know as little as possible about a movie before I see it, especially at a festival. I don't want to be pre-hyped, I don't like knowing much about the plot (though a basic sub-genre is OK), and in general I just want to get the experience I rarely get from major studio releases, where the nature of what I do (writing on the internet) leads me to know the ins and outs of a movie simply by osmosis. It gets to the point where knowing the major beats of a new blockbuster is akin to knowing that George Washington was the first President - I couldn't pinpoint exactly where I learned it, I just KNOW. Luckily, I got my preferred amount of knowledge for Satan's Slaves (Indonesian title: Pengabdi Setan), which is to say, almost nothing. All I had to go on was that I was told by a friend it had a great jump scare and that he really wanted me to see it, and the festival programmer mentioned Phantasm as an influence during his intro. Therefore, I was never ahead of the characters, never waiting for that great shot from the trailer to appear, etc. I was able to go on the journey with them, and enjoy the ride untainted by too much knowledge of where it was going.
Incidentally, even if I DID know the setup I wouldn't have guessed where it was going. This isn't a movie that dives into its horror elements right off the bat - writer/director Joko Anwar lets us get to know our protagonists a bit before springing the supernatural on them. Our main character is Rini, the oldest child (and only daughter) in a family besieged by financial troubles due to the sickness of their mother, a former singer. The royalty checks have dried up and the father is unable to make ends meet on his own, so they're facing homelessness, not to mention the possibility of not being able to afford any further medical care. The oldest son (of three) even sells his dirtbike to help out, and what struck me as rather unique about this sort of scenario is that he didn't begrudge his parents about the sacrifice - it almost seems like he did it on his own rather than by demand of his father. Therefore, we're instantly sympathetic to these people and hope they come out OK of whatever horror is about to be unleashed on them. Alas, the mother dies early on, and the father leaves them to head to the city to see about work and/or possibly moving into a smaller place. He's barely out the door before the children start seeing creepy things, and they just have to deal with it due to the fact that their telephone has been disconnected (per the aforementioned financial strains).
But I'll refrain from any further plot details, only to say that this is no generic haunting film and that even the title, once its context becomes clear, still doesn't quite paint a complete picture of what kinds of terror the family faces over the film's 100 or so minutes. In fact if I'm being perfectly honest some of the plot points are a little murky, and at least one subplot (concerning the children's biological origins) is left largely unresolved. However, that's the wonderful benefit of having sympathetic characters - I didn't really care about the specifics, only that they made it out of the ordeal OK. The tight bond between the kids is shown time and time again, with none of the usual sibling rivalry bullshit reducing their appeal. The youngest son, Ian, is deaf/mute, and the middle brother - who you'd expect to bully him or simply not care, protects him when he's scared and signs for his benefit. The older brother even uses some of his meager cashflow to get them a toy. It's these little details that go a long way to building a bond with the audience, something often forgotten in contemporary horror, where creating generic conflict often substitutes for genuine character development.
And it delivers the scares, though the structure keeps them mostly out of the first act. There's an all-timer involving a sheet being thrown over a painting, and a few effective variations of the standard "they think the scary thing is over there but then they turn to their side and it's right next to them" boo! moment. But again, it's not just ghost movie stuff; there's a whiff of supernatural/possession horror as well, and there's even an out of nowhere gore moment that recalls a particular kill in Argento's Deep Red. It's the kind of horror that thankfully does not sit squarely in one sub-genre, but is very much its own thing. It's also another winner from Anwar, who previously impressed with Ritual a few years back. Like that film (which had a standard "guy wakes up without knowing where he is or how he got there" intro that led to many surprise developments), Satan's Slaves isn't afraid to switch gears to keep the audience invested, and he seems to know that it's much more important to care about the characters than it is to 100% understand every single thing that happens to them (which, as I realized, is part of that aforementioned Phantasm influence). It's coming out soon; I recommend taking the ride.