A mind-bending Möbius strip of a movie, this indie sci-fi makes up for what it lacks in budget with a wealth of playful ideas. It’s a two-man show – directors Justin Benson and Aaron Moorhead also star in the film (which was written by Benson), as Justin and Aaron, a pair of brothers who escaped what Justin describes as a “UFO death cult” as children. Life in the real world, however, seems grimly disappointing compared with that in Camp Arcadia; a washed-out grey-green colour palette speaks volumes. So at the insistence of Aaron, the pair return to the camp for a visit. And confronted with an idyll of beautiful people bonding around the campfire, Aaron starts to question why they ever left.

Benson and Moorhead are canny enough to leave plenty of questions unanswered about just what it is that keeps the camp members so preternaturally young-looking and what prevents them from leaving. But while there is fun to be had trying to unpick the twisted logic behind the story, there are a few glaring plot questions I couldn’t quite resolve. What’s interesting is how little this actually matters. A lack of credibility would normally be enough to sink a high-concept indie picture like this – it undermined the tonally similar Another Earth. But here, the atmosphere and unnerving vignettes get under the skin. Like the brothers, we find it hard to escape the film’s sinister embrace.