Mother

Director Bong Joon-ho watched Psycho as he prepared his latest film, one of the most discomfiting visions of mother-love since Norman Bates last ran a motel. There is Hitchcockian perversity, too, in Bong’s casting of Kim Hye-ja, an iconic Korean actress specialising in benign mothers, as a far more troubled maternal spirit. This nameless mother will do anything for her son, which feels like a threat as much as a promise, as Bong’s gothically atmospheric melodrama plays out.

Hye-ja is the elderly single mother of Yoon Do-joon (Won Bin), a 27-year-old who has a child’s mental age, and is everyone’s dupe. Walking home drunk one night, he propositions a girl, who is found dead the next day. When he’s arrested, Mother, sure of his innocence but confronted by lazy cops and lawyers content that they’ve got their man, investigates the crime herself. This frail, nervy woman finds hidden reserves; living only for her son, the ties that bind toughen to unforgiving steel under the situation’s intolerable pressure.

Bong’s previous films, including smash-hit monster movie The Host (2006) and society-implicating police procedural Memories of Murder (2003), have made him the most domestically popular director in South Korea’s cinematic powerhouse. There’s little of the garish ultra-violence we expect from brilliant compatriots such as Park Chan-wook (Old Boy). Instead, Bong concentrates on the rain-drowned claustrophobia of his small-town setting, which the girl’s corpse is hung high enough to accusingly overlook. The alley she vanishes down when she rebuffs Do-joon (Won Bin, pictured right) is a pitch-black hole; an anti-matter zone of darkness where her death’s truth waits.

As Mother follows one false lead after another with growing tenacity, gaining a detective’s purpose she never had before, she uncovers the dead girl’s life of tragic promiscuity. Mobile phone photos of herself having sex with male schoolmates are collateral to keep her grandmother in the rice wine that’s rotted her brain. There’s something almost demonic about the sad and selfish lives this average little town secretes, as it sits under lashing rain.

Mother never quite tips into horror. Instead it’s a thriller whose grip relentlessly grows, helped by Bong’s Hitchcock-schooled icy, delicate touch. The scene where spilled water pools towards a sleeping suspect’s fingers as Mother tip-toes past him, golf club evidence in hand, has a cunningly balanced tension - not least because you’re not sure who’s in danger should the suspect wake.

This is an intricate whodunit in which everyone concerned is better off not knowing the answer, where solutions become trapdoors into deeper darkness. Everything hangs on the simple, unquestioning love of a mother for a son no one else can save, and how dangerous that can be.

• Mother is on general release
• Find The Host on Amazon