“Mother,” the new film from director Joon-ho Bong (“Tokyo!,” “The Host”) only reaffirms my belief that Godzilla is small potatoes compared to South Korea’s cinematic monsters. Edgy, bone-chilling and disturbing in ways a mainstream Western director wouldn’t dare attempt, “Mother” is a movie that will make you scream for momma.

The action of the film is precipitated when Do-joon (Bin Won), a man-child of sorts who lives with and sleeps in the same bed as his overprotective mother (Hye-ja Kim), is arrested for murdering a local school girl who he follows one night. After appeals to police for whom this is an open-and-shut case and lawyers who ignore her, his mother takes it into her own hands to track down the true killer and clear her son’s name. What follows is a grotesque and harrowing trip into her troubled relationship with her son and an exposé of the secret lives of children.

Bong proves himself a master of genre jumping; he feels equally comfortable delving into film noir as he does dabbling in the territory of dark comedy and psychological thriller. His mission is facilitated by the dynamic eye of cinematographer Kyung-Pyo Hong, a true artist of space and color. Hong turns small spaces into claustrophobic nightmares and large ones into heartbreaking expanses of solitary despair. But despite the duo’s stylistic schizophrenia, transitions from tone to tone are made with a masterful touch, whether that means terror triggered by the swift chop of a knife or a seduction set in motion by the swell of a violin.

Kim’s character complements the film’s unstable identity perfectly. While she delivers her lines with believable desperation, her skill is most apparent in moments of silence. She’ll break your heart with a quick glance at the floor or a twitch of her mouth, and no matter how insufferable her son may be, you never seem to question her motives. She is a mother, and mothers protect their young, even if that leads them into murky moral territory.

At its heart, “Mother” succeeds because it is so unabashedly transgressive. It takes our assumptions of kinship to uncomfortable extremes by posing questions to which it gives no discernable answers: When is the relationship between mother and child too close? Can the trauma embedded in that relationship ever be erased?

Alarming, tragic and perilously bottomless, “Mother” is sure to open up a whole new can of worms with your analyst. Come prepared.