This cleverly made thriller creeps up on the audience with an understated sense of horror.

[The film] pitches its tent in a disorienting space between nature and cult(ure), as Sean Kirby's initially lyrical camerawork takes on an increasingly hallucinatory urgency, and Keith falls prey to paranoia delusion.

They Remain, the first filmed take on [Laird Barron's] work, manages to replicate a gratifying amount of that distinctive vibe, infusing the story with large doses of free-form agoraphobic anxiety. It lingers.

"They Remain" does what it means to do. It makes the natural feel threateningly alien.

While it runs a bit too long, the direction is impeccable, the acting brilliant, and the ending pays off the slow build with something explosive yet heady.

A slow-burn psychological thriller like They Remain requires patience. It seems to be more about mood and paranoia than about plot or easy scare.

Stylish audiovisual feast for adventurous genre enthusiasts, even if the relatively slender storyline has to rank among the least of its inducements.

The movie's essential ingredients are simply two good actors, a lab compound, surveillance cameras and an eerie forest that may be driving the characters mad.

It's an engrossing exercise in boiling familiar ingredients down to pure, unbridled creepiness.

With little in the way of plot (the source material is a short story), this sci-fi-tinged horror film is carried solely by the actors and atmosphere, and in the case of the former, it mostly succeeds.

This is not a film for newcomers to the genre. It requires a familiarity with ancient things, yet it is in the unfamiliar that it anchors its emotional affect.