Returning unannounced with her pubescent son to the rural family homestead on the occasion of her estranged younger sister Pauline’s wedding, her initial motive of re-bridging the fissure with her sibling becomes promptly transparent as a means for her to escape the rocks of her own flailing marriage, and to pursue re-ignition with an old flame who, coincidentally, resides nearby.

The impenetrable shields of her duplicitous, back-stabbing intellect are only eclipsed by her razor keen ability to observe, detail and categorize the flaws of those around her. As it happens, this is not a tall order, as her arrival surrounds her with a small menagerie of broken, disreputable and pathetic new targets.

The supporting characters each have their own personal flavor of malfunction. Margot’s clingy confused young son, her sister’s layabout ne’er do well groom (Jack Black, in his straightest, possibly best performance yet), the unwashed hillbilly neighbors, the local writer with whom Margot once shared a bed and his jailbait daughter all would seem to exist as distinctly different walking models of how not to behave.

Although Kidman’s bitch-perfect performance as Margot is as formidable a one as you’re likely to see, it’s Jennifer Jason Leigh who really takes the movie. Her Pauline is the very reflection of her older sister’s dysfunction, but layered with an earnest, reaching hope for redemption completely lacking in Margot. Backed into a corner by her responsibility to the family home, a growing daughter and a “secret” baby on the way, she seems to be desperate to pull her life into focus, even as Margot actively and vociferously sabotages everything.

They spar with a candid mercilessness in front of kids, neighbors, family and friends about the most intimate of family issues—their abusive father (who appears only symbolically in the form of a diseased old tree on the property, which literally overshadows the whole film’s proceedings), old betrayals, how many people they’ve slept with—no subject seems taboo enough for them to resist or leave unexposed. Within all the judgment and antipathy, they do occasionally find common ground—the brief mention of the rape of their older sister (conspicuously absent, as is their mom, throughout the majority of the film), for example, results in peels of shared laughter, as they roll around on the sofa like a pair of schoolgirls. (Kudos, by the way, to the Paramount Vantage marketing team, which has apparently chosen to use a still of this moment as the core of its promotional campaign.)

It may not come as a shock that audiences, above average or otherwise, may find it difficult to relate to such a loathsome, sniping, mean-spirited bunch, but Baumbach manages to make them all believably, genuinely human. Jumping nimbly in and out of incidents and arguments, leaving many unresolved, he conveys a strong and affecting sense of the social claustrophobia and disassociation with which all these characters contend, although, in the film’s most glaring narrative flaw, not a one of them ever seems to make a whit of personal headway.

Under their skins, none of these monsters are truly as detached as they might appear on the surface, and it’s clear that beyond all the self loathing and emotional isolation, these people really do crave to be social. Kinda social, at least, as Hughes once wrote—demented and sad, but social.