Prophet Malcolm (Michael Sheen) has drawn people from all over and preaches equality and fairness in return for worship and sacrifice. The cult (for that is what it is) look superficially like some Christian Sect using similar words in their teaching but they worship something older but also more tangible.
CW: Violence, mutilation and bloody sacrifice.
I went in cold not knowing much about this and was pleasantly surprised. It's got an overlap with The Wicker Man (outsider goes to island run by a religious cult looking for somebody, discovers weird shit) but isn't any kind of rehash.
What it does to distinguish itself from a lot of horror is have the bulk of the movie being the attempt to retrieve Jennifer with weird stuff happening very much in the background.
There's lots of "small community" problems: young members having an illicit relationship, internal power struggles, greed, secrets and worries about outsiders. Prophet Malcolm is painted mostly as a grifter with a bunch of heavies to back him up. It seems he's done something terrible elsewhere and has people after him. Michael Sheen is great as Malcolm.
Once the blood starts to flow it gets grim but oddly positive. Thomas is delivering on a promise rather than being a victim.
Recommended 8/10.