‘Sleep’ Review: Bumps in the Night

Apnea, insomnia, sleep hygiene, sleep aids, sleep tricks: It’s all science but feels like sorcery. Even the most rational person can begin to suspect, three weeks into sleepwalking spells or 3 a.m. wakefulness, that some curse has been placed upon them, and the only cure is some mystical spell. It’s the stuff of horror, and the director Jason Yu harnesses it deftly for his debut feature, “Sleep,” a neatly constructed thriller about the sort of insanity that slumber issues can visit on even the most harmonious household.

The household here is made up of the newlyweds Hyun-su (Lee Sun-kyun) and Soo-jin (Jung Yu-mi), who is heavily pregnant. They live in a modest apartment with Pepper, their fluffy and beady-eyed white Pomeranian. On their living room wall hangs a plaque proclaiming a cheerfully optimistic notion: “Together we can overcome anything.” This sentiment, we understand, is about to face a great challenge.

First it’s Hyun-su’s sleep disturbances. He scratches his face bloody in the night — a problem, since he’s an actor who is in the middle of shooting a minor part in a TV show. He sleepwalks, and sleep-eats. When Soo-jin observes him in the night, she realizes he is gorging himself on weird and gross food — raw meat and eggs — and she starts to worry, with mounting fright, for Pepper’s safety. Hyun-su seems to not be himself at night. What is he capable of?

The couple consult a doctor and take precautionary measures, but Hyun-su’s sleep activities are taking their toll on Soo-jin, who sleeps less and less, especially once the baby arrives. He offers to stay in a hotel for a while; she is convinced they need to be together: As the plaque says, they can only overcome anything together. At the same time, Soo-jin’s superstitious mother tries to talk them into less orthodox cures, and Soo-jin, red-eyed and nearly delirious from constant, wakeful vigilance starts to wonder if her mother has a point.

Yu’s direction is confident, and he manages to convey how a little apartment can transform from domestic comfort by day to claustrophobic agony by night. His restraint throughout keeps us guessing. We really don’t know what’s plaguing Hyun-su. Is it nerves, or a neurological disorder, or some dark and shadowy force? Soo-jin doesn’t know either, and it scares her on several levels. But when Soo-jin’s state of mind deteriorates, Hyun-su becomes just as worried about his wife, who, after all, just gave birth, and wouldn’t be sleeping well no matter what.