At any moment, the Korean psychological thriller “Sleep” could have easily changed course and become a mediocre horror comedy. Instead, it’s a finely tuned (and creepy) marriage drama in which one partner suffers from a severe case of sleepwalking while the other worries about it, making it both a paranoid thriller and a slow-burn ghost story. In his impressive debut, writer-director Jason Yu strikes a delicate balance between character-driven and high-concept horror. It helps that co-stars Jung Yu-mi and the late Lee Sun-kyun have great onscreen chemistry as a weary but close-knit couple. But “Sleep” continues to walk such a fine line in its depiction of a relationship in crisis that it takes a moment for Yu’s quick, confident stride to register as his film’s greatest asset.
Neither cheesy nor conventional, “Sleep” moves briskly with its characters as they try to unravel what may or may not be a spooky mystery. First, Hyun-su (Lee) wakes up from a deep sleep. “There’s someone inside,” he murmurs. Neither Hyun-su nor his pregnant wife, Soo-jin (Jung), can determine what that means. He believes they can track, diagnose and quarantine his new problem as a project that can be advanced through trial and error. She, being an emotionally involved (though not passive) observer, takes a darker, more harrowing path.
Some familiar themes and tropes shape “Sleep’s” convoluted plot: What will become of Hyun-su and Soo-jin’s baby, and what exactly does their nosy downstairs neighbor, Min Jeong (Kim Gook Hee), know about what’s going on? There’s also generic intrigue involving a shaman, Madame Haegoong (Kim Kum-soon), who comes recommended by Soo-jin’s anxiety-fueling mother (Lee Kyung-jin), and a doctor (Yoon Kyung-ho), who happily provides Soo-jin with placebo reassurances.
To its credit, Yu also doesn’t shy away from the kind of generic encounters one might expect given that it centers on a sleepwalker and his child in peril (Have you checked the trash, dear?). But “Sleep” focuses primarily on the subtle, episodic challenges Soo-jin and Hyun-su face along the way. The trick to this kind of film is that one has to want to follow both protagonists as they realize that, despite their best efforts, they’re not exactly on the same journey. Yu succeeds by foregrounding and then consistently affirming Soo-jin and Hyun-su’s relationship even as they go through a horror story that puts them at odds.
Better yet, Yu never gets lazy in his portrayal of Soo-Jung, a co-lead who arguably has to be not only level-headed despite her ever-escalating paranoia, but also scared in a way that makes her concerns seem like more than just a collection of the usual horror movie pretexts. Jung is good here, and so is her screen partner, but Soo-jung excels in all the little ways Yu emphasizes her motivating fears of losing her husband. It’s one thing to suggest that Soo-Jung wants to stay with Hyun-su no matter what. It’s another thing entirely to get a finely sketched yet rounded portrait of a stressed-out married woman through modestly scaled conversations with her mother, her partner, her neighbor, and so on.
Lee fans will likely see what they expect from “Sleep” despite the high expectations that come with his role, which happens to be one of his last. It’s not a very showy performance, but Lee is still perfectly emblematic of what makes “Sleep” so special; he’s not only a commanding lead, but also a generous screen partner. He’s an integral part of Yu’s well-balanced overall picture, as are the film’s scary scenes, which are never excessive or programmatic despite the brief, overwhelming presence of Miss Haegoong. Rather than ending with a big supernatural showdown, “Sleep” climaxes with an emotional outpouring that, with a hard push in either direction, could have been laughably over-the-top or hilariously petty. It’s neither, because while Hyun-su inevitably airs her grievances, Soo-jung also (perhaps) meets her wife on her level.
More than anything, “Sleep” stands out thanks to Yu’s delicate yet surprisingly thoughtful consideration of Soo-jin and Hyun-su, who complement each other even as they grow apart. “Sleep” also never overwhelms viewers with a tidy or heavy-handed statement or prescription about what married life and parenthood can or should look like. Rather, Yu stops exactly where he must in order to protect and maintain “Sleep’s” suggestive atmosphere and charming ambiguities. I can’t wait to see what Yu does next.