South Korean thriller ‘Sleep’ is bitingly funny and tense

Yu's feature debut starts out in gentle, acerbic territory, unveiling a pitch-black comedy about a young woman dealing with her husband's strangeness in the middle of the night. Jump scare fake outs and nosy neighbors paint a tongue-in-cheek portrait, as Yu keeps us at an arm's length from Soo-jin's anxiety. However, as Hyeon-soo's midnight actions grow more concerning—he scratches his own face until it bleeds, and scares their Pomeranian, Pepper, in the process—the film begins slipping towards horror territory, even though it lays its cards on the table.

The culprit is almost definitely a REM sleep disorder. A doctor confirms as much, but neither his authoritative delivery, nor Hyeon-soo's reassurance over being diagnosed, calms Soo-jin's nerves. After all, from her point of view, Sleep is about a woman vulnerable to violence, with no easy way out of a dangerous household. She's eager to make it work, and so is Hyeon-soo, but when a downstairs neighbor asks her about loud sounds and screams—for which Soo-jin apologizes—the invisible specter of domestic violence rears its head, inducing a quiet sense of dread.

Sleep isn't explicitly about this subject—in fact, Hyeon-soo is gentle and loving, at least when he's awake—but the movie's gendered undercurrent is hard to avoid. Several characters, including the aforementioned neighbor and even Soo-jin's mother, approach her conundrum with advice about rituals, and with outdated, impractical wisdom about how to get herself out of this situation. The problem is Hyeon-soo's, and Hyeon-soo's alone, and yet, Soo-jin is subtly made out to be the culprit—as though patriarchal norms are slowly closing in on her from all sides— until her own paranoia starts to take on harmful forms.

Over the course of the movie's 94 minutes, Yu gradually transitions the movie's point of view over from Soo-jin to Hyeon-soo, keeping the audience firmly on the outside of whoever's mind is unraveling in a given moment. While this distancing approach might seem to work against its human drama, it's wildly effective when it comes to inducing a sense of lurking terror, as both Soo-jin and Hyeon-soo—one after the next—are forced to experience doubts about their partner, and question how well they truly know them.

Hyeon-soo may not be violent in his daily life, but the film often hints that his episodes are connected to his waking anxieties. Things he says and thinks of during the day manifest at night; he repeats lines from the scripts he learns, and his worry over failing at his craft even leads to sleepwalking self-harm. It ought to follow, in the film's own dramatic logic, that something about him might be violent too, a conclusion towards which the viewer is subtly nudged, perhaps without fully realizing.

This was one of Lee's final roles before his passing. The Parasite actor rounds out Hyeon-soo in lovable ways, but he also uses tricks of body language and posture to make him seem quietly frightening once the sun goes down. Sometimes he sits still at the foot of the couple's bed. Other times, he lurches towards the refrigerator, or towards Pepper, in ways that verge on threatening, even though he doesn't necessarily attack. It's a performance laced with possibility, and Jung responds in kind, making Soo-jin absorb and ruminate on each and every potential outcome in the process.

Notably, the film's supernatural element isn't dismissed out of hand. It bears a passing resemblance to the boisterous Bollywood comedy Bhool Bhulaiyaa (2007) in that it uses horror hallmarks and a tale of possession to center a story rooted in a character's crumbling mental state. The question of what's actually going on with Hyeon-soo is frequently broached, but no matter where one falls on it as an audience member, Hyeon-soo and Soo-jin are pushed so far beyond the brink of exhaustion by their predicament that any possibility becomes worth considering too.

Sleep works because there's a slickness to Yu's filmmaking. A protégé of Parasite director Bong Joon-ho, his debut is appropriately watertight, without a moment wasted on unnecessary images or information. His montages of passing time are clear and concise, but they also center the couple's intimate body language in casual moments, so that the movie feels like it's coming apart at the seams when Hyeon-soo's sleep issue becomes too much for them to bear.

No matter what genre tropes or subversion Yu tackles, he remains fixated on Hyeon-soo and Soo-jin's interpersonal dynamic, even when it seems to shatter beyond repair. This in particular makes Sleep a fantastic dramatic thriller about the lengths people are willing to go to for those they love, regardless of the harm it causes their loved ones, or themselves.