“Together We Can Overcome Anything” reads a decorative burnt wooden board in the efficient and modestly decorated apartment of the newlyweds Hyun-su and Soo-jin. The South Korean version of a “Live, Laugh, Love” portrait hanging on the wall of a couple’s townhome somewhere in Maryland, perhaps, though Hyun-su and Soo-jin’s family motto has a slightly more menacing bent to it. “What’s to be overcome?” one might consider. And what if being together is itself the obstacle to be vanquished? South Korean director Jason Yu’s directorial debut, Sleep, gets to the bottom of that fire-branded adage.

Sleep opens on the very pregnant Soo-jin, a captivating Jung Yu-mi, waking in the night to find her husband Hyun-su, played by the late Lee Sun-kyun of the cast of Parasite, talking in his sleep as loud bangs emanate from the other room. Worse events follow as Soo-jin begins to notice that Hyun-su is having trouble sleeping; read: scratching his face until it bleeds, and eating raw meat, eggs, and fish straight from the refrigerator. Something is going on and with a baby on the way, Soo-Jin is willing to try everything from medicine to mysticism to save her husband.

Jung Yu-mi Is Mesmerizing In Her Leading Role As Soo-jin

Hyun-su & Soo-jin’s Chemistry Lifts The Film

Though Sleep is pulling from the long history of South Korean horror and thriller movies — not least of which is Parasite, considering how often the hilt of a carving knife is tapped on like a piano — the movie is centered on, and driven by, the lovely relationship between Hyun-su and Soo-jin. If Sleep was edited down to its daytime sequences, the movie would be a wonderful romantic comedy, complete with an intervening mother-in-law and nosy downstairs neighbor. As it were in a ghost movie, both may have a point by wondering what’s really going on in Soo-jin’s apartment.

The doting relationship between the couple does some heavy lifting for the film and even in the third act (so conveniently announced by chapter cards that appear throughout Sleep), when things nearly go haywire, their believable bond papers over any horror movie lapses in logic. Yu is also wise enough to primarily put the focus on one half of the couple and Jung delivers.

Jung, whose popularity in South Korea is more representative of her talent than most American audiences would credit her for, is totally at home in her role as Soo-jin. A quick rapping on the small of her back, a mimed blow dart at her husband, and a thumbs up so big it threatens to cover the screen are the tiny decisions that make Soo-jin not just adorable but trustworthy. She’s not too meek for the horror, either. Soo-jin’s slow eye creeps from her husband to their barking dog after he devours the contents of their fridge is a horrifying harbinger.

A Third Act Stumble Is Not Enough To Knock Sleep Off Course

Sleep Keeps Us Guessing Until The Very End

Most of Sleep takes place in a tiny two-room apartment and Jason Yu uses just about every camera trick he can think of to expand the space. The camera goes in close to an eye, then backs out to show the whole room, then quickly swings into what looks like an over-the-shoulder hand-held camera shot. He goes above, backward, up, down, and around. You’ll feel like you’re in a New Order song. It’s disorienting, and while that might be an intended effect for a horror movie, it can also feel like we’re occasionally missing something just out of frame.

As often as his uninhibited film style confuses, it also leads to some excellent moments, such as a shot that goes through a mirror and back out the other side as if entering another dimension. One of the more frightening moments in the film comes towards the end when Hyun-su returns to his home after a disorienting car ride. The familiar wide shot of his living room is transformed as we slowly realize every surface is covered in ancient yellow prayer sheets.

The third act does threaten to knock the smoothly gliding Sleep off its rails. Fortunately, Yu pulls back just in time, and what could have brought the movie to a lurching end, is quickly remediated in anticipation of a few more legitimate shocks. Sleep may over-explain the terror that Soo-jin and Hyun-su are facing, but their believable unwillingness to let the other go ensures that we’re kept guessing about each outcome until the very last shot.

Sleep is now playing in theaters and is available to watch on digital. The film is 95 minutes long and is currently unrated.