As portrayed by Gerwig, Brooke is a fascinating creature, an avatar of the gig economy ("I've always been good at curating my employment," she says) as well as the encroaching panic of young middle age.
Kirke delivers a wide-eyed, watchful performance as Tracy, who soaks up Brooke's every word and gesture with admiration and avidity. She is a budding writer, and while she loves her new best friend, she sees a deep vein of literary gold in her. Like Baumbach's While We're Young, Mistress America explores the fine line between hero worship and vampirism, as well as the squishy ethics of artistic appropriation.
Like his other collaboration with Gerwig, Frances Ha, Baumbach again gives audiences a rare glimpse of a young woman establishing her own identity. Keenly attuned to the striving and solidarity of female friendship, Baumbach gives both of his heroines plenty of leeway, as well as compassion. Mistress America doesn't shy from these subtexts, but it doesn't entirely give into them, either. By the time the two women take a raucous day trip to Connecticut, it's clear that Baumbach and Gerwig are far more interested in the daffy possibilities of Brooke and Tracy's journey, than its dark side.
To appreciate this sequence it's probably best to give in to Baumbach's somewhat archaic comic rhythms. He brings the story back home, with confidence, pathos and pleasing karmic balance.
It's tempting to call Mistress America sweet, given its fizzy wit and the mutual delight of Kirke and Gerwig's camaraderie. But it would be missing the essential honesty at the film's centre. Mistress America offers a lovely bookend to a similarly restless exploration of friendship, aspiration and writerly envy, The End of the Tour, except that here each woman's tour is just beginning. Even at its most daft and infectiously ditzy, Mistress America is a sharp, aware and kind portrait of the agony and ecstasy of becoming yourself.
Rated M
84 minutes
Out Nov 26