This review contains spoilers.

At the Brattle Theater in Cambridge on April 6, Wicked Queer Film Festival spotlighted Aino Suni’s “Heartbeast,” an intense story of infatuation turned obsession between flawed young artists.

“Heartbeast,” a mostly French-language film, follows Elina (Elsi Sloan), an aspiring rapper who has to move from Finland to France so her mother can move in with her new boyfriend. Elina quickly becomes obsessively enamored with her mother’s boyfriend’s daughter, Sofia (Carmen Kassovitz), a privileged dancer struggling to keep up with the high expectations of everyone around her.

Suni’s direction makes “Heartbeast” a must-watch. The film’s highly saturated, vibrant color palette aptly portrays the high running emotions and tensions of the main characters. For example, the stunning blue sky during a fraught outdoor family lunch features mostly static camera work as the characters ignore, insult, and misunderstand one another. This makes the film’s few scenes with dark, strobe lighting and those with quiet, muted moments of connection stand out in the bazaar.

This contrast is particularly evident when Sofia and Elina first share a connection. In a quiet scene at night outside where Elina helped Sofia through an anxiety attack, Elina watches Sofia dance and is inspired to frantically write a song in her honor. The contrast between the quiet nighttime scene, and Sofia’s chaotic, dramatic dance performance in the dark broken up by flashing lights creates a sense of breathlessness — further emphasized by shots of Elina with a bright spotlight on her back as she scribbles frantically, writing Sofia a love song. This dicotomy perfectly encapsulates the film’s thesis about the overlap and generative power of art and obsession, as in this moment Sofia creates a connection with Elina and shows off her talent for dance, while Elina is inspired both to get closer to Sofia and to take her music more seriously.

The slow escalation of Elina’s obsession with Sofia is well-paced, as she starts out as largely sympathetic. Initially, Elina’s insecurity masks a lot of her psychotic tendencies, her harm of those around her steadily going from regrettable mistakes to disturbingly intent. On the other hand, Sofia is introduced as very self-centered, as she lavishes Elina with attention only when she is bored or stressed. But over time, this is tempered by revelations of how overwhelmed and burdened Sofia is by her father and dance school’s expectations. And as the film continues, her selfishness becomes a function of how she is devoted to her craft and desperate to be successful.

The film opens by underscoring Elina’s shyness as she hides at a party and then becomes too overwhelmed to freestyle with her friends, despite being an aspiring rapper. During the title credits, as she walks home in the dark and raps passionately to the city skyline. The camera follows her from behind, creating a strong image of a desperately aspiring but insecure young artist, for whom fame and recognition are just out of reach. Sloan’s acting — with an understated affect and careful use of body language when Elina is calculating how to manipulate someone — is powerful throughout.

Elina’s actions become more and more reckless and dangerous as the film continues, however, causing active harm to everyone around her as she tries to keep Sofia to herself. Sofia tolerates and even enjoys it at first, craving her undivided attention when she isn’t occupied with her dancing, and only begins to become concerned after it threatens her life. But instead of devolving into a stereotypical flight of the victim or a cheap slasher, Sofia’s sociopathic disregard for other people’s feelings becomes clearer as Elina’s actions become more horrifying. Sloan’s deadpan expressions and flat, coaxing voice while Elina manipulates the people around her is chilling, and in combination with the natural, expressive manner Kassovitz brings to Sofia, their devolving relationship is electric to watch.

The motif of the song that Elina crafted for Sofia — which effectively began Elina’s obsession — supports the arc of the film exceptionally well. The song appears in full three times — one with only Elina frantically scribbling the lyrics cut with Sofia dancing, later in full when Sofia unwittingly plays the song in front of all her friends at a party, and then onstage at a performance, where Sofia hears a new, extended version and realizes that not only is Sofia in love with her, but Elina will do anything to control her. Sofia’s reaction to this moment characterizes the film, as its choice to avoid stereotypes, trite messaging, or a neat ending makes “Heartbeast” a magnetizing watch.

— Staff writer Millie Mae Healy can be reached at milliemae.healy@thecrimson.com.