I knew I'd seen the names of the guys behind this film before. They made the slightly oddball 2014 romantic horror fantasy Spring, which had a tone and milieu all its own that we seldom see in horror or sci-fi.

This film has the same wild imagination and a nice Hitchcockian sensibility that makes you eager to discover the truth about what's going on.

In the end it explains itself less successfully than you want it to (or it might just be that the explanation is a little on the weak side), but I remember being similarly nonplussed by the resolution in Spring even though it worked in a narrative sense.

This time the writer/directors play brothers with their own names, Aaron and Justin, who escaped a desert commune religious cult as young boys years before and now run a cleaning business.

Now men in their 20s, the pair are struggling. Despite Justin's efforts to take care of his brother Aaron can't move on, frustrated by his ability to make friends or meet a girl, and the pair struggling to make ends meet in their dead end job.

When they receive a VHS videotape that shows a woman at the camp talking about something called 'the ascension, Aaron tells Justin he wants to go back and get the closure he feels he needs, especially because both boys's memories about what they endured are very different and Aaron wants to finally learn the truth.

Justin is against it – to him 'ascension' is codeword for a mass suicide so the UFO gods they worship can pick them up in their spaceship (in a nod to the Heaven's Gate cult of the late 90s) and he's scared if they go near their former home they'll get swept up in it again for good this time.

But he reluctantly agrees and when he and Aaron get out of the car at Camp Arcadia, they couldn't be made to feel more welcome by many of their former friends and associates including camp leader Hal (Tate Ellington) and pretty Anna (Callie Hernandez) who Aaron's always held a torch for.

Aaron falls back in with everyone effortlessly and even Justin has to admit the experiences he remembers might not be the nightmares he's always thought.

They reconnect with everyone and stay overnight in one of the cabins, Justin starting to relax a little bit, but it's during a fireside ceremony the following night that things get properly weird.

Part of the proceedings is for participants to tug on a rope that extends out of the circle, across the desert sand and up into the dark night out of sight, as if it's tied to a giant or dinosaur who pulls viciously at it.

But it's just the first sign something weird and maybe supernatural is going on. While jogging around the surrounding semi-arid forest, Justin becomes convinced something's watching him. A polaroid photo of a buoy on the lake drops from the sky and Hal later tells him the answers he wants will be found in the water at the bottom of the lake below it.

He takes Aaron fishing at the designated spot and dives down to the retrieves a box that contains another videotape, this one showing the brothers as young boys talking to the news about awful cult activities at the Camp that never happened.

The boys and Hal argue, Hal saying he has to forgive them for telling the outside world they're religious nuts and child abusers, Aaron angry at his brother for apparently coaching him to remember lies about the place when they could have been happy there, and when Justin insists they leave, Aaron refuses.

Justin gives up, trying to leave by himself but finding their car won't start. Instead he stumbles off into the desert. The first clue about what's actually happening comes when he finds his way to a remote cabin, opening the door in shock to find the occupant has hanged himself inside, but with the same profane, sarcastic guy emerging from the night to tell Justin he's stuck there, doomed to relive his death over and over.

But there's much, much more. The weird fulgurites that dot the landscape actually have a very sinister purpose. At one point we close ominously in on a campsite made up of an old-time calico tent, a sudden movement inside repeating over and over and a 19th century ticking clock hanging on the outside snapping back five or so seconds when it does.

There's a creepy guy around the camp who stares, smiling widely. Another guy who stomps angrily around and ignores Justin's every effort to say hi. Three moons hang in the sky, something everyone tries to convince the guys is just an atmospheric phenomenon.

I'm not going to say any more about what's actually going because that's what you're there for, and whether it satisfies you will depend on how neatly you like mystery stories settled.

I wasn't completely sold on either the answer or the way it was handled, but until then The Endless (and there's your first clue) does an effective job of setting the clues up and delivering them with an appreciably unsettling tone that draws you in.