Playing like an overheated Tennessee Williams drama in which all three members of a suffocatingly intimate family are deranged, The Beautiful Beast maintains a consistent tone of simmering unease. Imagine if Williams' Cat on a Hot Tin Roof was set on an isolated, pastoral French-Canadian estate, and you begin to get the vibe created by director Karim Hussain. Hussain adapted the debut novel by Canadian author Marie-Claire Blais, published when she was just 20. Blais was educated by Roman Catholic nuns; while the story, as told by Hussain, does not tackle religion directly, it is a de facto attack on conventional morality and conversative values. The film version, swathed in allegorical fantasy, tends to unravel rather than unfold; we feel less like we're watching dysfunctional family dynamics than being taught a lesson in human depravity.

The widowed Louise (Carole Laure) takes the lead as the family visits cruelties upon one another. She calls her beautiful daughter Isabelle-Marie (Caroline Dhavernas) "ugly" for smiling at her equally gorgeous brother Patrice (Marc-André Grondin) at the dinner table. What seems to be an unhappy mother-daughter relationship is turned sideways when Isabelle-Marie finds Louise and Patrice far too clingy with one another at bedtime. Are they carrying on an incestuous affair? Is Louise so jealous for her son's affections that she was offended when Isabelle-Marie smiled at him?

The squeamishness continues the next day when Isabelle-Marie invites her brother to take a naked dip in a nearby river while she watches. She claims this is her attempt to spend more time with her brother, even as their interplay edges uncomfortably toward open flirtation. Once Patrice is fully immersed, she reminds him that their father drowned in the river, which, again, turns the relationship on its side. Is Isabelle-Marie trying to seduce her brother? Or does she want to hurt him to get back at her mother?

Louise leaves the two home alone while she travels out of town to attend a funeral. Isabelle-Marie and Patrice horse around a bit, and then Isabelle-Marie locks her brother in his room. At first it seems to be an extension of their games, but too much time passes, and when she finally unlocks the door, Patrice is weak and frail. He's soiled himself and torn up his room in frustration. Desperately hungry, he searches for food in the house, but Isabelle-Marie claims there isn't any, that their Mother is responsible for not providing for them, though we've already seen the young woman enjoying a meal. It's difficult to fathom what would cause Isabelle-Marie to be so inexplicably cruel to her brother. Certainly sibling jealousy and adolescent resentment can be powerful motivating forces, but Isabelle-Marie's actions clearly go beyond the pale.

Louise returns with the studly Lanz (David La Haye) in tow. She met him at the funeral and is already planning their future life together. The children are naturally enraged, but Louise cares not at all about their feelings. Shunted aside from his position as the primary recipient of his mother's love, Patrice begins to act out; at one point he quite seriously throws a big rock at Lanz' head. Louise insists that that she will soon marry Lanz, which causes Patrice to demonstrate his unhappiness with the arrangement in a more dramatic fashion.

Isabelle-Marie is a study in contrasts. On the one hand, she is happy that Patrice has been demoted, in effect, to her level of inattention and disinterest from their mother. On the other hand, Lenz has simply replaced Patrice as the apple of her mother's eye, and Louise is still insulting and demeaning to her. She finds her own lover, Michael, a handsome young man with no greater desire than to bed Isabelle-Marie. Their romance is fleeting but very meaningful for Isabelle-Marie, and sets the stage for the final cruelty she will visit upon her family.

The Beautiful Beast looks sumptuous, with muted autumnal colors predominating. The visuals match the languorous pace of the tale. The pace, and very occasional surreal nightmarish touches, lends credence to the idea that the story is better taken as allegory than any kind of explainable reality. It really does feel to me like a film that desperately wants to tell the world how horribly people can treat one another, especially within a family. Yet that message is undercut by the river of insanity -- or at least severe mental instability -- that runs through Louise, Isabelle-Marie and Patrice. If everyone in the family is mad, that gives them a reason for their twisted actions. Or are the filmmakers suggesting that the entire world is mad?

I don't know. But what I do know is that Caroline Dharvernas is compulsively watchable. While Carole Laure is stonily indifferent and Marc-André Grondin too often has a stupid grin plastered on his pretty face, Dharvernas navigates troubling emotional waters with finesse. If anyone in the film engenders sympathy rather than pity, it is Isabelle-Marie, and that's due entirely to Caroline Dharvernas' performance. If only all the elements of The Beautiful Beast worked as well as she did, I might be telling you about a little-seen gem instead of a well-meaning disappointment.