An newlywed couple are plunged into a nightmare scenario when the husband develops a sleep disorder that may reveal a disturbing split personality with possible supernatural overtones in writer-director Jason Yu’s intense feature debut. Expectant mother Soo-jin (Jung Yu-mi) awakens one night to the eerie sight of her husband, Hyun-su (Lee Sun-Kyun ), sitting at the end of their bed, muttering that ‘someone is inside’, before collapsing into a deep sleep. In the days that follow, his disturbing nocturnal behaviours, of which he has no recollection, escalate, and the couple’s once-idyllic relationship begins to deteriorate under the mounting paranoia that Hyun-su might inadvertently hurt himself, Soo-jin, or their unborn child. Having worked under South Korean luminaries like Lee Chang-dong and Bong Joon-ho, Jason Yu displays a natural gift for character, story, and tension in this expertly calibrated genre piece.

Notes by David O’Mahony