Brooke, Greta Gerwig's latest Manhattan creation, is a hurricane gobbling up lives. She's a singer, restaurateur, interior decorator, math coach, spinning instructor and self-described autodidact. When 18-year-old admirer Tracy (Lola Kirke), Brooke's sister-to-be following their parents' Thanksgiving wedding, squeaks that she wants to write short stories, Brooke devours that idea, too — only, as she insists, her as-yet-unwritten fiction will be longer.

Brooke can't help being the focal point of Noah Baumbach's Mistress America, though Tracy, an adrift college freshman, is its supposed star. Watching, we're all absorbed by Brooke and her delusional Dorothy Parker–esque pronouncements. “There's nothing I don't know about myself,” she declares. “That's why I can't go to therapy.” Yet everyone — including Tracy — knows that the Brookes of the world eventually run out of hot air.

Like Brooke's dream business, a café/convenience store/hair salon, Mistress America is a mishmash of ideas — fortunately, Kirke's fantastic performance quietly grounds the film. The beginning and end work as, respectively, a naturalistic comedy about impressionable girls and a drama about the same. Baumbach and co-writer Gerwig nail the details of proto-adulthood, Tracy's college dormitory screwdrivers giving way to Brooke and friends' countless bottles of wine. Ginned up by Brooke's moxie, Tracy blooms from wallflower to budding Big Woman on Campus. Despite her infatuation with her role model, Tracy writes a piece about who Brooke really is, albeit through the eyes of a kid who thinks that anyone pushing 30 is “dragging around the rotting carcass” of their youth.

In a wicked and perfect gag, Brooke gets confronted by a former classmate she bullied in high school. At first, she fakes nice, like a popular kid bestowing her grace. Yet when the woman presses for an apology, Brooke's noblesse oblige turns into a shiv. Unlike Tracy, she's purposefully cruel.

But in the clumsy middle sequence, set in a Connecticut mansion, Baumbach inserts a screwball farce that stops the movie cold. He derails our investment in this imbalanced sisterly relationship to insert a half-dozen extraneous characters — a crush, a jealous girlfriend, Brooke's patronizing ex, a pregnant stranger, a bitter neighbor, a maid — and uses them as weapons to attack Tracy and Brooke's overinflated egos. The casting is fine, and Heather Lind, as the ex's hostile new wife, is excellent. Yet as the centerpiece confrontation drags on, interest fades fast, especially when every actor stops playing an individual to stab one another with same-y quips.

What's special about Mistress America is that Brooke is a uniquely millennial monster: a money-grubbing idealist. Though in person she's full of harsh one-liners, she knows to frame her online persona as a Zen messiah, tweeting such banalities as “Teach yourself something new.” Yet crucially, when Brooke is forced to take the stage and defend her latest life goal, Baumbach, too, seems to fall for her BS. She sounds nuts. But the people listening grin and nod. And if neither them nor the movie can withstand Hurricane Brooke, we've all got to run for cover.

MISTRESS AMERICA | Directed by Noah Baumbach | Written by Baumbach and Greta Gerwig | Fox Searchlight | Landmark, ArcLight Hollywood

Advertising disclosure: We may receive compensation for some of the links in our stories. Thank you for supporting LA Weekly and our advertisers.