Ever since The Cabinet of Dr. Caligari, horror has been entrenched in themes of sleep, possession, and mysticism. Films like Cat People and Suspiria have explored this theme in fascinating ways, despite the stylistic differences between European folklore and Giallo’s aesthetic. Writer-director Jason Yu’s Sleep carries on this rich tradition by melding horror with an edge-of-your-seat domestic drama.
Set in South Korea, we follow pregnant Soo-jin (Lee Sun-kyun) and her actor husband, Hyun-su (Jung Yu-mi). Their normal life goes awry when Hyun-su begins to act strangely as they wind down for sleep each night. He started by muttering but soon developed weird symptoms such as intensely scratching his face and being hungry for raw meat. The doctor reveals that hHyun-su e has an REM sleep disorder. Changes are made in the household, such as removing alcohol and locking up sharp items. Despite these alterations, Hyun-su continues his strange sleepwalk. Eventually, Soo-jin discovers their pet Pomeranian, Pepper, dead in the fridge.

“…Hyun-su begins to act strangely as they wind down for sleep each night.”
As the couple deals with supernatural problems, the downstairs neighbor is annoyed with the late-night noises. Soo-jin tries to develop a friendship with her. The friendship starts normal until she notices the neighbor’s son has a pet Pomeranian. She begins to ask questions about the absence of the old man who used to live in the same apartment. It turns out he was the deceased father of the current tenant. He was known to complain about the couple’s dog and was virtually obsessed with Soo-jin. She begins to put the pieces together but still wonders how the old man factors into Hyun-su’s possession.
Sleep is engaging from beginning to end. Yu creatively structures it into three chapters, building suspense for the twisted climax. Yu-mi and Sun-kyun portray a believable couple through their realistic performances. Alongside the suspense and strong acting, there is social commentary and thought-provoking thematic concepts. A major theme is medical versus spiritual help, which plays a key role in Soo-jin’s arc.
Sleep follows the trend of philosophical horror, which has been popular ever since Jordan Peele’s Get Out. By touching on the intellectual approach, Yu has crafted a highly entertaining film with realistic characters.