Henry James was onto something over 100 years ago when he zeroed in on the true victim and best observer of a divorce, a child, in “What Maisie Knew.”

Now that novel has been modernized and freely adapted into a brilliant, soul-aching portrait of the break-up of two self-absorbed adults and the very young child trapped — helpless — between them.

What Maisie knows, even at about age seven,  is that her parents (Julianne Moore, Steve Coogan) aren’t getting along.

Mom;s an aging, chain-smoking rock musician. Dad;s a work-obsessed art dealer with a wandering eye and a mean mouth.

Susanna curses. Beale eviscerates.

“I’m done with my midlife crisis,” he hisses. You should get on with yours.”

They never married, but they’ve been together for years. So even as he moves out, there are custody issues to haggle over. “Be sure to factor in 30 years of substance abuse” when you’re describing him to the judge, Susanna snaps at her lawyer. “I’m fixing things” is all dad tells his little girl.

Moore and Coogan are fiercely unlikable here, playing characters that worry about career, tonight’s party and later tonight’s hook-up with barely a thought for Maisie. The child (the wide-eyed Onata Aprile) can only watch and absorb mom’s irresponsible all-night musician party (when Maisie has a friend sleeping over) or dad’s haste in taking up with the young Scottish nanny, Margot  (Joanna Vanderham).

Filmmakers Scott McGehee and David Siegel (“The Deep End”) and the screenwriters set first one parent up as the worst, then the other.

The only caregivers who bother to connect with Maisie are that nanny turned step-mom, and mom’s bartender boyfriend (Alexander Skarsgard) whom she marries to try and wrest custody from her ex-husband. But they’re out of their depth, unsure of their standing. And like Maisie, they’re on the sidelines — victims of the birth parents’ negligence, self-absorption and hatred for each other.

The story is told in quick sketches — short scenes where Maisie has a hopeful moment in the park or the recording studio, interrupted by mean mom accusing her new man of making the kid love him, or dad’s promise to take Maisie or Margot on a trip only to break that promise a moment later.

Moore is at her brittle best, quizzing the kid on her dad’s failings as a father, unleashing unfiltered tirades at everyone who adds to her “I can’t handle this” load. Coogan lets us see his disdain for the pretty but unworldly Scots lass he has married to complete his revenge on his ex-wife, and to provide live-in child care.

And young Onata Aprile makes Maisie a passive wonder, a sweetly poker-faced, nonjudgmental and hopeful child, even as she’s being ditched at bars, forgotten at school or passed back and forth like a prize, or a bad penny.

 

MPAA Rating: R for some language

Cast: Julianne Moore, Onata Aprile, Alexander Skarsgaard, Steve Coogan, Joanna Vanderham

Credits: Directed by Scott McGehee and David Siegel, scripted by Nancy Doyne and Carroll Cartwright, based on the Henry James novel. A  Millennium release.

Running time: 1:39