Mother (2009) is a deliberately paced combination of thriller and drama that is closer in tone to Joon-ho’s earlier film, the melancholy Memories of a Murder (2003) than the crowd pleasing monster movie The Host (2006) although there are similar themes exploring how family units function (or more often don’t function). Joon-ho uses narratives to help broaden our understanding of his central characters, often surprising us in the way our expectations develop and are altered. On a simplistic level Mother is about a mother’s over-protection of her son, driven to absurd lengths to ensure his safety, but the film broadens this to provide a more complex picture of its apparently two-dimensional, singularly motivated characters. Everything is depicted clearly and yet nothing is quite as it seems. The viewer is granted enough intelligence to unravel the details without the director ever resorting to simple exposition.

Yoon Do-joon (Bin Won) is not the brightest young man in town, although he gets mightily riled when anyone suggests this is the case, and he suffers from sudden bouts of vagueness and temporary amnesia. His mother (Hye-ja Kim), a shopkeeper with a sideline in unlicensed acupuncture, feels duty-bound to keep a watchful eye on him, especially as she doesn’t trust Yoon’s so-called best friend Jin-tae (Ku Jin). When he’s slightly injured in a hit-and-run accident Do-joon, goaded and ‘aided’ by Jin-tae into getting revenge, track the men in the black Mercedes to a golf club and enact a clumsy form of vengeance on the affluent group. Do-joon is arrested and it’s down to mother to plead for the boy. However, he soon forgets the importance of the incident and gets slowly drunk waiting for a date that never arrives, and was never going to. His apparent lasciviousness and a gap in his memory on the walk back home lead him to the prison cells once more when the body of Moon Ah-yong is found hanging over a balcony, a golf ball signed by Do-joon found next to her body. This time mother really has to pull out all the stops to prove that her son is innocent and get him back home.

Mother is at its best when it contrasts its naturalistic style with the absurdities of life, which is where it finds its darkest humour. Following his arrest (which comes across more like a kidnap in broad daylight) Do-joon is cajoled into signing a confession to a crime he claims he didn’t commit through a bizarre martial arts and fruit ritual – what is later referred to as "apple biting human rights abuse". Later, at a farcical reconstruction of the murder a handcuffed Do-joon cannot resist giving a cheery wave even as the morbid crowd of on-lookers strain to see the police fumble with a silver mannequin that’s meant to represent the unfortunate victim. Indeed it’s these fumbling moments, the occasional character trips or mispronounced words that lend the film a realist perspective even among the little day-to-day fantasies that the film depicts, such as uninhibited and unashamed dancing in fields. This is a film where memories are fragile, recollections fragmented and perceptions tainted.

Central to proceedings is the titular mother, played with stern-eyed intensity and occasionally naïve happiness by Hye-ja Kim. Although her raison d’etre in life is apparently simple – protect her son – her motivations and methods are not. Although much is made of the fact that she sleeps next to her son, the film is pointedly ambiguous as to how far the relationship has gone, the intimacy appears on the surface to just be abnormally over protective. She still feeds her son his dinner despite the fact that, in his twenties, Do-joon is trying to get a semblance of normality into his life, even if he is not fully capable of controlling his actions or thoughts. Her dogmatic belief in her son’s innocence leads her towards a dangerous investigation, determined to prove to the police that her child did not commit the crime.

Full of incidental detail and intriguing plotting Mother is an engaging, human and humorous thriller that is markedly different from the normal procedural murder drama, and is far more engaged with its characters and their inner workings than in the banality of forensic crime.