Leandra Leal in A Wolf at the Door (Outsider Pictures)

Every parent’s nightmare takes place in this searing Brazilian drama, which has a Greek flavor in the way it makes children pay for the sins of the father and a Japanese influence in its Rashomon-like structure.

When Sylvia (Fabiula Nascimento) arrives to pick up her six-year-old daughter, Clara, from school, she is told by the bemused teacher that she just missed the girl. Per Sylvia’s instruction, Clara was picked up by a family friend. As the story gets teased out in a police station, it becomes clear that someone posing as Sylvia called the school, giving permission for Clara to go home with another woman. But she wasn’t a stranger, the teacher insists; Clara was excited and gave this person a hug.

At the police station, Bernardo (Milhem Cortaz), Clara’s father, admits to the interrogating inspector that he has been having an affair and suspects his mistress, Rosa, must be have taken Clara as a joke. But Rosa (Leandra Leal), once brought to the station, claims ignorance of the whole situation, at first. Not until the adulterers offer an alternate telling of their affair are the layers of fiction peeled away from the truth. (The plot’s based on an incident that occurred in the 1960s.)

The story is compelling and ultimately shocking, supported by top-notch filmmaking. Lula Carvalho’s cinematography is full of shadows, increasingly appropriate as the lies begin to pile up, and when the camera doesn’t cut away from Sylvia during her interrogation, for instance, it makes her seem that much more alone.

Long takes are also used to illustrate the spectrum of sex and violence in Bernardo and Rosa’s affair. First, they generate real heat together without the aid of flashy edits or a steamy score. Later, in a terrifying scene, Bernardo exercises physical and emotional power over Rosa, and the lack of an edit makes the moment painfully relentless.

It’s a good thing the sex is hot, because no other reason is given for the lovers to be so explosively and inextricably connected to each other. There’s little character development in their initial meetings, and the dialogue is (appropriately) full of the dopey things people say when trying to be sexy. There’s never evidence of genuine compatibility between them, and we must believe the physical passion is enough to turn what started as a lark into a poisonous pas de deux. Just when the film risks turning into a knockoff Fatal Attraction, a twist sends the plot into its own, uniquely pitch-black place.

A Wolf at the Door is wicked entertainment, with the grim justice of a fairy tale and the lingering unease of a good ghost story.