She's a real mother; so's the movie

Kim Hye-ja, motherhood and madness make a toxic mix.

The jazz that I most closely associate with the 1950s and '60s had a spirit of defiance, a capacity for lyricism and a taste for experimentation. The musicians were pushing boundaries, and if they sometimes lost their way, they were forgiven. There's really no precise equivalent in film, but watching Korean director Bong Joon-ho's Mother, I wondered whether something close to the probing, sometimes playful quality of jazz hasn't distinguished Bong's work. Like a jazz musician, Bong searches for novelty within familiar frames.

In The Host -- a movie about a monster that threatened Seoul -- Bong found ways to unify a variety of disparate genre elements, riffing on them while at the same time respecting their potency. In Mother, Bong does much the same thing, only the movie is far more unsettling than The Host, which I never took all that seriously. Both movies are deeply strange, but Mother has more haunting power.

The story Mother tells is nothing if not weird. Twenty-seven-year-old Do-joon (Won Bin) lives with his mother (Kim Hye-ja). Kim's character is both solicitous and possessive of her grown son, a young man who seems to be mentally impaired, although it's not clear how much debilitation he suffers. He and his mother sleep in the same bed, but their relationship doesn't seem to have become overtly incestuous.

The movie's lack of clarity may be intentional on Bong's part: He creates an atmosphere in which lines blur and the purest emotions can become hopelessly twisted; i.e., a mother's love for her son can become so overpowering that it leads her into territory that borders on perversity – and, no, we're not talking about sex.

Notably, we never hear a word about a father in Do-joon's story, which eventually turns into a murder mystery. Do-joon is arrested for the murder of a young woman (Moon Hee-ra) whose body is found draped over a wall on the roof of a building. Lacking other suspects and possessing one piece of incriminating evidence, the police conclude their investigation. For the cops, it's an open-and-shut case.

Believing that her son is incapable of murder, Kim's character begins to investigate. She eventually involves one of Da-joon's pals, a slick, knowing fellow named Jin-tae (Jin Goo). Jin-tae also may be a suspect in the crime.

The murder of a schoolgirl does not conclude the film's cycle of violence or bring any sense of closure to an open-ended plot. The key to appreciating Bong's work involves deriving pleasure from watching loose ends dance in winds generated by characters who are ill equipped to understand their own motivations. We don't always know precisely what's happening, but Bong's visual skills and Kim's performance keep the movie from falling apart.

Kim's performance is a powerhouse of mixed messages. She plays Mother with a mixture of quiet endearments, ferocious determination and extreme vulnerability. Kim is one of those actresses who can appear attractive and welcoming one second and appalling the next. Kim's character is a kind of uncontrollable force – a mixture of healing urges and undisguised ferocity, most of it expressed in attempts to protect her son.

Do-joon isn't easy to understand, either. He can be as defiant as a balky adolescent or as naïve as a toddler. Usually, his face reveals little. He's a mama's boy with all the baggage that brings. He rubs his temples when he's trying to remember something. As it turns out, he has plenty to remember.

Mother works on a variety of levels; it's a powerful expression of realities that seem ungraspable, a twisted murder mystery, a dark comedy and a bizarre character study that puts any number of conflicting psychological forces in play. Bong's particular brand of genius allows this quietly crazy movie to be all of a piece, even as it pushes toward the most terrible extremes.