In his sophomore directing effort, Jason Bateman again opts for a script that begins as authentically dark comedy but eventually winds its way to a conventionally upbeat ending—and includes a plum part perfectly suited to his own mixture of snarkiness and vulnerability. Like “Bad Words,” “The Family Fang”—adapted by David Lindsay-Abaire from the well-received novel by Kevin Wilson—goes a mite soft at the close, but along the way it’s a mostly bracing tale of how the eccentricities of parents can affect their children.

The couple in question are Caleb and Camille Fang, played in flashbacks to an earlier time by Jason Butler Harner and Kathryn Hahn and in the present by Christopher Walken and Maryann Plunkett. The pair are a team of guerilla performance artists, who have built a career of sorts by staging public scenes designed to involve unsuspecting observers and record their outraged reactions. When the Fangs have kids—Annie (first Mackenzie Brooke Smith, then Taylor Rose) and Baxter (first Jack McCarthy, then Kyle Donnery)—they include them in the act, and the emotional scars are apparent now: Annie (Nicole Kidman) is an actress whose career in crumbling, and Baxter a novelist whose struggles with a third book—after a stellar debut and a disappointing follow-up—have forced him to take on embarrassing freelance work, like covering a bunch of vets who amuse themselves shooting off super-powered potato guns.

It’s that assignment that lands Baxter in the hospital with a head wound, leading the staff to summon his long-estranged parents to take him home. When he enlists Annie to come back east to give him support during his stay at their place, it gives Caleb the chance to excoriate both his children for their failed artistry while extolling his own. Meanwhile Camille, clearly the follower of the two (an enabler, to be more precise), aims to keep the peace as much as possible, even after Caleb, desperate to revive the old magic, enlists the siblings in a goofy fake-coupon bit that falls flat—an outcome for which he blames them.

That leads to the crux of the plot: Caleb and Camille go off on a road trip, leaving Annie and Baxter behind, only to wind up missing, possible victims of a rest stop killer. Annie is certain that it’s just one more publicity scam designed to resuscitate their fame, while Baxter isn’t so sure. As brother and sister wend their way through past and present—eventually winding up at the estate of Caleb’s college mentor Hobart (Harris Yulin) for answers—they confront the truth but more importantly learn to leave their old traumas behind and embrace the future liberated. (Precisely how is up to the viewer to find out.)

The theme of Wilson’s book—the toll that parents’ obsessions can take on their hapless children (which is delivered pointedly in Walken’s final diatribe, in which he declares that it’s virtually a father’s fate to damage his offspring, and no less in a ditty called “Kill All Parents” that practically bookends the story)—is conveyed expertly in Lindsay-Abaire’s script and Bateman’s nimble direction, which manage a good balance between the serious and the darkly comedic. Bateman and Kidman, who along with her co-star served as one of the numerous producers, offer strong, nuanced performances as the grown-up Baxter and Annie, but the throbbing heart of the picture is Walken’s quiet ferocity as true-believer Caleb, almost maniacally certain of his artistic calling. He’s abetted well by Plunkett as his over-devoted spouse, and those who play the younger versions of all four characters handle themselves well too, without attempting direct imitations. The smaller roles are also well filled, with Yulin exuding the vibe of an eccentric but loving uncle, while Linda Emond and Marin Ireland make strong impressions as women who impact the Fangs in very different ways. There’s also a delicious insert in which Scott Shepherd and Steve Witting appear as dueling art critics assessing the quality—or lack thereof—in Caleb’s output.

On the technical side one can appreciate Beth Mickle’s convincing production design and Ken Seng’s ably unostentatious widescreen cinematography, which is nicely juxtaposed with the grittier flashbacks by editor Robert Frazen. But perhaps the most memorable craft contribution comes from Carter Burwell’s gossamer score, which integrates bits of Beethoven at crucial moments.

Though it ends on a hopeful note, “The Family Fang” is by no means a feel-good portrait of family life: the acidic, abrasive undercurrent remains to the end. While it centers on a family weirder than most, though, it’s a surprisingly biting—and enjoyable—rejoinder to the bland Waltons Mountain portrait of parents and children that movies and television so often paint.