At any given moment, the Korean psychological chiller "Sleep" could have easily switched gears and become a lame horror comedy. Instead, it's a fine-tuned (and eerie) marital drama where one partner suffers from a bad case of sleepwalking while the other worries about it, so it's both a paranoid thriller and a slow-burning ghost story. In his impressive debut feature, writer/director Jason Yu strikes a fine balance between character-driven and high-concept horror. It helps that co-leads Jung Yu-mi and the late Lee Sun-kyun have great on-screen chemistry as a weary but well-attached couple. But "Sleep" still treads such a fine line in its depiction of a relationship in crisis that it takes a moment for Yu's quick, sure footing to register as his movie's greatest asset.
Neither sudsy 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 dead sleep. "Someone's inside," he murmurs. Neither Hyun-su nor his pregnant wife, Soo-jin (Jung), can determine what that means. He thinks they can track, diagnose, and quarantine their new problem like a project that can be chipped away through trial and error. She, being an emotionally invested (though hardly passive) observer, goes down a darker, more harrowing path.
Some familiar stakes and tropes give shape to "Sleep"'s twisty plot: What's to 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 some generic intrigue involving a shaman, Madame Haegoong (Kim Kum-soon), who comes recommended by Soo-jin's anxiety-stoking mother (Lee Kyung-jin), and a medical doctor (Yoon Kyung-ho), who happily provides Soo-jin with placebo reassurances.
To his credit, Yu also doesn't shy away from the sort of generic encounters that you might expect given his focus on a somnambulist and his endangered child (Did you check the trash, dear?). But "Sleep" mostly concerns the subtle, episodic challenges that Soo-jin and Hyun-su face along the way. The trick to this type of movie is that you have to want to follow both protagonists as they realize that, despite their best efforts, they're not exactly on the same trip. Yu succeeds by foregrounding and then consistently affirming Soo-jin and Hyun-su's relationship even as they cycle through a horror story that puts them at odds.
Better still, Yu never gets lazy in his portrayal of Soo-Jung, a co-lead who arguably has to not only be sensible despite her perpetually escalating paranoia but also scared in a way that makes her concerns seem like more than a collection of the usual horror movie pretexts. Jung's good here, and so is her screen partner, but Soo-jung stands out in all the little ways that Yu emphasizes her motivating fears of losing her husband. It's one thing to suggest that Soo-Jung wants to stick with Hyun-su no matter what. It's another thing entirely to get a finely sketched but complete portrait of a stressed-out married woman through modestly scaled conversations with her mother, her partner, her neighbor, etc.
Lee's fans will still likely see what they're hoping for from "Sleep" despite the heavy expectations that come with his role, which happens to be one of his last. It's not a very showy performance, but Lee's still perfectly emblematic of what makes "Sleep" so special; he's not only a commanding leading man but also a generous screen partner. He's an integral part of Yu's well-balanced big picture, just like the movie's load-bearing scare scenes, which are never excessive or programmatic despite Miss Haegoong's brief, overwhelming presence. Rather than end with a big supernatural showdown, "Sleep" climaxes with an emotional unburdening that, with a hard nudge in either direction, could have been laughably over-the-top or hilariously mean-spirited. It's neither, because while Hyun-su inevitably airs her grievances, Soo-jung also (maybe) meets his wife at her level.
More than anything, "Sleep" stands out thanks to Yu's delicate but surprisingly thoughtful consideration for both Soo-jin and Hyun-su, who complement each other even as they drift apart. "Sleep" also never overwhelms viewers with a tidy or heavy statement or prescription for what married life and new parenthood can or should be like. Rather, Yu stops exactly where he needs to to protect and maintain "Sleep"'s suggestive atmosphere and charming ambiguities. I can't wait to see what Yu does next.
