Justin Benson and Aaron Scott Moorhead are a tactile duo, crafting thought-provoking, effects-driven, genre-defying features filled with big ideas on a micro-budget. Their last film, Spring, which can only be described as a “romantic body horror” and was a favorite for many who sought it out after its 2014 Toronto Film Festival debut, failed to find much of an audience among the general public but solidified the partnership, who had previously collaborated on 2012’s low-budge horror flick Resolution, as a pair for cinephile’s to keep a close eye on. Rather than pulling in the reins, the creative partners have gone even bigger with The Endless, a heady science-fiction-slash-horror—slash-cult-thriller-slash-sibling-drama that’s ambitious to a fault.

Following in the footsteps of Borderline Films (Martha Marcy May Marlene, James White, Simon Killer), Benson and Moorhead have taken on an awe-inspiring amount of roles on their sets. Between the two workhorses, they’ve taken the reins in the writing, directing, editing, cinematography and producing departments. This time they’ve divvied things up between them as follows – Moorhead is credited for directing, producing and cinematography while Benson earns credits for directing, writing, producing and editing. They both also star in The Endless.

Their third feature is as predictably unpredictable as those familiar with their previous efforts might expect, a miasma of cult thriller and science fiction enigma. Justin (Benson) and Aaron (Moorhead) are two brothers who years ago escaped a UFO doomsday cult. They live small, unfulfilling lives, cleaning houses to scrape up rent money. They lack any semblance of community, their tiny existence lived in stark opposition to their cordial communal roots.

When a videotape arrives in the mail inviting them to come make a final visit before their former commonwealth departs for good, the dissatisfied Aaron pleads with his older brother to return, if only to bury the hatchet and free up any lingering doubts about the true nature of the group. Were they right to flee? Was there ever any real suicide pact in place? Or did they leave behind the only place they ever felt at home for no reason at all?

The directing-writing-producing-editing team toy with these questions for the next hour, introducing us to a mild-mannered group of self-dependent do-gooders who inhabit the camp; a collective of beer brewers, clothing designers and organic farmers who all genuinely seem to look out and care deeply for each other. But there’s a lingering rumor that none of the guys have their nether regions anymore (which may prove unsubstantiated) and that’s enough to keep the two now-outsiders weary of the welcoming tribe.

As if a castrated doomsday UFO cult isn’t left field enough, The Endless charters a course into even more bizarre otherworldly territory when it starts to (satisfyingly) unraveling the mysteries it has thus far presented. Moorhead and Benson being Moorhead and Benson, that’s not enough and The Endless melts and moves and shapes into an entirely different beast as it moves into its final act, including elements of sci-fi, thrillers and horror movies to make something that defies easy explanation. As characters seek to understand the depth of the situation they’re in, Moorhead and Benson introduce a number of memorable and clever tableaus whose intelligent minimalism may remind viewers of Shane Carruth’s devious sci-fi stunner Primer.

Admittedly, Moorhead and Benson may have overextended themselves taking on the two leading roles – the acting is where the film suffers most – but one must appreciate the DIY attitude these two adapt to execute their vision. If they can’t find the right guys for the job? Screw it, they’ll do it themselves. So too is it plenty easy to see the seams in some of the larger-scale FX work – a conflagration engulfing a man and his cabin, a scene-swallowing car chase – but when The Endless abandons retrograde CGI and uses its limitations to its advantage, victories are won. A moonlit game of tug of war where the rope extends seemingly infinitely into darkness; an inexplicable pair of moons hovering on the horizon; the unexplainable fact that none of the cult’s membership has seemed to age a day in dozens of years; each conjure up a palpable fear of the unknown with hair-raising skill, weaponizing our suspicions into unsteadying daydream fuel.

There’s so much that goes on in The Endless but I fear divulging anything more would be an absolute disservice to the mind-boggling hysteria everyone involved with The Endless worked so hard to create. Even with a handful of shortcomings, Moorhead and Benson have made yet another fascinating entry to their filmography, one that champions big ideas over numbing spectacle and further signals a pair of rising stars just waiting for their eventual recognition.

CONCLUSION: Moorhead and Benson’s ‘The Endless’ is a riveting trip down the rabbit hole, fastened with a smarter-than-average and genuinely thrilling script and impossible to predict plotting. Suffers in the acting and special effects department but remains a strong recommendation for sci-fi fans looking for some original flavor.