“The Julia Set” arrived at the Toronto Film Festival with two clear calling cards: Chase Infiniti has her first film showcase since her breakout turn as the daughter of Leonardo DiCaprio’s character in “One Battle After Another,” and writer-director Niki Byrne emerges from the premiere as a filmmaker with a sharp command of both performance and story.
Infiniti plays Julia Fischer, a first-year college student and math prodigy whose formidable intelligence becomes both her gift and her vulnerability. The film follows Julia as she enters a romantic relationship with Pascal, her teaching assistant, played by Christopher Briney of “The Summer I Turned Pretty” and the musical version of “Mean Girls.” What begins as intellectual chemistry between two mathematically gifted young people becomes a thornier portrait of ambition, desire and emotional imbalance.
Byrne, who wrote and directed the movie, is working here on her second dramatic feature. “The Julia Set” can be read as a coming-of-age drama, but its most distinctive hook is the way it frames Julia’s genius as central to the stakes. Her future is not an abstract idea; it is tied to real academic possibility, family loyalty and the pressure of proving herself in a world where talent is constantly measured.
A prodigy under pressure
Julia is presented as brilliant without being showy about it. She has little ego wrapped up in her talent, and that makes her a particularly compelling figure as the story places her in situations that test not only what she knows, but what she is ready to understand about people. Infiniti’s performance captures a young woman who is disciplined and self-possessed, but still inexperienced enough to be pulled toward someone she should be wary of.
Pascal’s interest in Julia carries tension from the start because he is her teaching assistant. The film acknowledges the complications of that dynamic while also showing why the two are drawn to each other. Their connection is built in part on a shared mathematical language: they are both gifted, both fluent in a world most people around them do not fully inhabit, and their exchanges turn academic conversation into flirtation.
That pull becomes more dangerous once Pascal invites Julia into an advanced study group led by Dr. Zatlan, played by Nina Hoss. Dr. Zatlan is preparing students for the Putnam Competition, described in the film’s world as a fabled math test made up of just 12 questions. The competition has been around for 100 years and is widely considered the most difficult math test ever devised. The school is competing as a team, but each participant is also individually measured.
For Julia, the competition is more than an academic challenge. It could become a path to MIT, a school she had already gotten into, along with Harvard, the University of Chicago and several others. Instead, she is attending a modest local college because it offered her the best scholarship and allowed her to stay near her family: her loving mother, played by Carmen Ejogo, and her beloved older brother Evan, played by Alex Dillard, who has Down syndrome.
The bad romance takes shape
“The Julia Set” does not present Pascal as simply an admirer of Julia’s mind. His attraction to her intelligence is tangled with competitiveness. One of the early warning signs comes after he performs poorly on a sample test, storms out of class, slaps himself, punches a bulletin board and yells, “Fuck!” From there, the film continues tracing a relationship in which red flags do not automatically result in escape.
Byrne’s drama is interested in why people remain in situations that outsiders might see clearly. Julia is not written as foolish; she is written as young, ambitious, emotionally open and caught between several versions of the life she wants. She wants to be a prodigy, a success, a devoted daughter and a person in love. The film places those desires in conflict rather than letting them sit neatly beside one another.
The story widens when Pascal brings Julia to meet his parents. His father, Andrew Mandelbort, is a legendary mathematician played by Jason Isaac. Andrew is shown as narcissistic and competitive with his son, and the film uses a chess scene between father and son to reveal the shape of their relationship. Pascal’s mother, played by Gillian Anderson, adds another emotional layer to that family portrait.
As Julia is pulled deeper into Pascal’s orbit, the movie builds toward a climactic math competition while also incorporating Adderall abuse, a car accident, gaslighting and personal reckonings. Those plot developments are not presented as isolated melodramatic shocks, but as pressures accumulating around a young woman trying to hold together intellect, love, family and ambition.
The festival takeaway is that “The Julia Set” gives Infiniti a rich vehicle after “One Battle After Another,” and she carries it as a true character study. Byrne’s control of the material is equally central: the film’s mix of academic stakes, romantic danger and family obligation depends on precision, and the premiere positions both actor and filmmaker as the major discoveries of this math-driven drama.