This is a fine exercise in arthouse horror — don’t expect elaborate monsters, an orchestral score, or CGI effects.

It Comes at Night directed by Trey Edward Shults. Screening at AMC Boston and the Somerville Theatre.

Kelvin Harrison, Jr. as Travis in a scene from “It Comes at Night.”

By Peg Aloi

You missed a phenomenal debut if you didn’t see Trey Edward Shults’ drama Krisha. The film is ostensibly about a Thanksgiving dinner attended by a middle-aged recovering alcoholic whose family treats her like a child who is prone to misbehave. As events spiral out of control, the film moves  into the realm of terror. This change in tone is partly due to Shults’ masterful use of sound to deftly modulate the narrative’s pitch and mood. The 2016 low budget debut wound up on many critics’ top ten lists. If Krisha was a drama that eventually generated the aura of a horror film, the reverse could be said for It Comes at Night, an artful effort in genre-ambiguity that keeps Shults in the category of filmmakers to watch.

Despite the fair amount of hype claiming that the film is one of the scariest to come along in months, rabid horror buffs might initially be disappointed by the story’s slow build, ambiguous exposition, and subtle intensity. In other words, this is an exercise in arthouse horror — don’t expect elaborate monsters, an orchestral score, or CGI effects. Granted, the beginning sets a horrifying note: an elderly man covered in weeping sores sits in a dark room, breathing laboriously. A woman wearing a gas mask tells the man she loves him, and says goodbye. The man is then bundled onto a wheelbarrow by two men, also wearing gas masks. One of the masked men asks the dying man if he has anything he wants to say, and the other masked man says, “Goodbye, Grandpa.” They then wrap him in canvas, shoot him in the head, tumble him into a hole, douse him in gasoline, and burn the corpse. When the masks are removed, we see a small family comprised of Paul (Joel Edgerton), Sarah (Carmen Ejogo), and their teenage son Travis (Kelvin Harrison, Jr.). They’re living in a house with boarded up windows, shelves full of canned goods, and no electricity. It seems as if sort of catastrophic plague has stuck humanity, with 100% mortality and 100% communicability. The only way to avoid contracting the disease is to avoid contact with the infected.

It sounds like a set up for a zombie movie, but this one is grounded in the commonplace. This is a world of virulent diseases (possibly, plausibly, developed and weaponized by our military–shades of Stephen King’s The Stand, minus any overarching religious context or shady paranormal powers). Soon after their unsentimental though still traumatizing disposal of their patriarch, Travis discovers an intruder in the house. Judging by his scrambling for his gas mask even as he grabs his gun, we can tell Paul’s more afraid of infection than of violence. Still, he confronts the intruder, a young man we later learn is named Will (Christopher Abbot). Paul’s first priority is his family’s safety, but after grilling Will at gunpoint, then leaving him tied to a tree overnight (to ensure no one followed him) Paul agrees to help Will, whose wife and small child are at an encampment 50 miles away. They are running out of food and water. Water needs to be elaborately boiled and purified in this brave new world, and food consists of canned goods and bagged grains stored on shelves. One wonders if the well-appointed cabin Paul, Sarah, and Travis live in, seemingly abandoned by its owners, had these supplies laid by, prepper-style, before the plague arrived. The family’s circumstances are never made clear: Shults doesn’t give us any extraneous expository detail, neither are there any clear signposts about location or time. We take these people as they are.

In agreeing to help strangers, Paul takes on unknown risks. Paul tells Sarah not to come looking for him if he doesn’t return. He takes Will in his pick-up truck to retrieve his family. They barely get ten miles before they are shot at, and they manage to overtake the shooters. Will is angry that Paul kills them before questioning them about other people, supplies, etc. It seems Paul has developed an avid distrust of almost anyone, and his decision to help Will preys on his mind. But he meets Will’s wife Kim (Riley Keough) and their toddler Andrew (Griffin Robert Faulkner — hey, why is it the smaller the person the longer the actor’s name playing them? Just wondering …), and the loving family seems like it might be a good clan to wait out the apocalypse with.

The first meeting at the house is cautiously friendly. Paul explains the house rules to the newbies. (The only door is always kept locked, everyone must travel in twos when venturing outside.) A montage gives us scenes of warmth, laughter, and community. Clearly both families had been starved for companionship. Travis is a quiet and thoughtful teenager (Kelvin Harrison, Jr gives a subtly compelling performance) who seems to be cast in the role of silent narrator. He observes the couples in his midst and continues to have disturbing nightmares, mostly about his grandfather. He sleeps alone in a large attic room with his dog Stanley, both in separate twin beds. But the arrival of Kim excites his 17-year old psyche, and he dreams of her, too, and even listens through the rafters to the intimate sounds of Kim and Will’s lovemaking. Unable to sleep one night, the two have a friendly chat in the kitchen, and Kim notices Travis staring at her. Will the burgeoning attraction between them cause tension or problems? By now we’re wondering: what is the “it” that comes at night? Nightmares are a given, as Travis’ terrifying episodes show. But since we see no odd emanations or events, it seems the title refers to the most fundamental of human frailties: fear and loneliness.

Stanley the dog disappears one night, and returns so visibly sick that Paul euthanizes him immediately. Travis is visibly traumatized by his pet’s untimely death, perhaps shattered by the realization that he’s even more alone in the world than before. From this point forward, the pall of dread never really abates, and fear of terrible illness hangs heavy over these survivors. But, as any consumer of post-apocalyptic literature will tell you, social collapse turns out to be far more damaging than any disease, contamination, or supernatural calamity. Survival manuals about finding stuff often leave out how to deal with the breakdown of civility and compassion. The parallels to today’s doomsday watchers are hard to ignore, though not overly heavy-handed. The house in the woods may be a setting, or a metaphor, or a commentary: just what happens to our humanity when we turn our homes into fortresses in an effort to feel safe in a dangerous world? And the thing that comes at night, every night, hounding us until we die? Pure existential dread.

Peg Aloi is a former film critic for The Boston Phoenix. She taught film and TV studies for ten years at Emerson College, and currently teaches at SUNY New Paltz. Her reviews also appear regularly online for The Orlando Weekly and Diabolique. Her long-running media blog “The Witching Hour” has recently been moved to a new domain: themediawitch.com