Pieta is more fun to write about than it is to watch. This is a film with an abundance of ideas, all executed with a preponderance of dense symbolism tangled within grim, disturbing imagery that distracts, rather than complements its themes. It’s not a pleasant viewing experience, sodden with violence and sordid sexual themes. There’s a lot to think about, but little to enjoy.

The story concerns a remorseless, ruthless loan shark who charges exorbitant interest and collects by crippling his debtors and taking the insurance. He encounters a strange woman who claims to be his mother; he treats her assertion with violent skepticism then acceptance. The first act of the film contains the majority of the unpleasantness; it opens with a wheelchair-bound man committing suicide and then features merciless violence and an impure, incestuous bond between the loan shark, Gang-Do (Jeong-jin Lee) and his apparent mother, Mi-Son (Min-soo Jo).

Pieta takes its name from Michelangelo’s sculpture of the Virgin Mary cradling Jesus in her arms, and this allusion is not accidental. Mi-Son is a complicated figure, representing sacred innocence and vengeance at once; the Old and the New Testaments together. She is more than that, too; the story is a twisted version of Dickens’ A Christmas Carol, with Mi-Son the Ghosts of Christmas Past, Present and Yet to Come. Gang-Do encounters the victims of his cruel modus operandi, physical manifestations of guilt left in rags or serene acceptance. The parallel seems intentional: director Ki-duk Kim lingers on chains and locks and hooks – like those that encase Marley’s Ghost in Dickens’ tale – and finds the loan shark in a living grave by the last act, as did the Ghost of Christmas Yet to Come.

Symbolism is omnipresent. Gang-Do’s apartment is piled with rubbish, while all his victims seem to toil at oppressive machines that are perfect for both punching holes in belts and irreversibly hobbling men. This machinery evokes a sense of inhumanity, the same sense of cruel capitalism that Dickens railed against in his Christmas parable. When Gang-Do ventures from the tangled dirty streets, the hills are invariably painted golden-brown, the colour of a land dying.

But this carol does not deserve to stand along Dickens. The characters here are personifications of despair, vengeance, hope, redemption, suffering, ruthlessness … but they aren’t people. This seems to be a conscious choice, to work in archetypes like a Leone western, but it works against the moments of distasteful, often sexual violence. The camerawork is predominantly handheld, the zooms similar to that of an amateur home video, and it’s out of place with the grander themes Kim seems to want to interrogate.

Ultimately, Pieta finds itself torn between the demands of a gritty, naturalistic crime drama and a larger-than-life meditation on guilt and the possibility of redemption. Despite the intriguing ideas at its centre, it feels like two immiscible halves churned together to produce a foul concoction, the raw, unpleasant dirtiness poisoning the film’s attempts to ponder loftier concepts.