There’s a touch of Roman Polanski-style claustrophobic horror to the Argentine thriller Penumbra, from brothers Adrián and Ramiro García Bogliano. Aside from an introductory scene, the film is entirely set in an atmospherically run-down Buenos Aires apartment building and the store across the street, between which the high-strung Cristina Brondo paces as she tries to arrange a rental agreement with a group of ominous real-estate agents. Or are they? Brondo’s too busy to pay attention. She lives in Spain most of the year and makes sure everyone knows it, along with how much she resents having to come back to her family’s home in Argentina, a country she puts down constantly.

Brondo and her sister inherited the spooky apartment and only want to make money off it, which is why she accommodates more than a few strange requests from Berta Muñiz, who claims to have a tenant willing to pay four times the asking price. The film is set in something close to real time, as Brondo negotiates with Muñiz and his slowly arriving colleagues and lacerates or lies to her coworkers on the phone. A solar eclipse is taking place that afternoon, and there’s a sense of growing dread as the self-interested protagonist remains willfully oblivious to signs that something’s going wrong.

Penumbra makes the provocative choice to have its main character be absolutely awful—insulting, condescending, and egotistical, qualities she demonstrates during her calls, as well as her encounters with a neighbor in the building and a homeless man on the street. The result is the audience spending the film wanting something terrible to happen to her, which isn’t conducive to scares. And since the movie is one long build-up to a reveal, it offers a lot of time to learn to hate Brondo and everything she represents. The eeriness of the setting is effective—the film gets a lot out of the unreliable, old-fashioned cage elevator and the dark, twisting staircase—but the protagonist is comically bitchy, which diffuses any tension, even as the characterization is used to make her seem like an unreliable witness to everyone nearby.

The crumbling building and the conviction Brondo has that civilization in the city is following suit give Penumbra an interesting undercurrent of privileged panic, but the film’s reveal is a disappointing anticlimax, made worse by how long the film delays it. Atmosphere and mood can support a thriller for a long time, but the payoff needs to be worth it, whether it comes in pesos or in euros.