From creepy insane asylums to experimental theater and even questionable pseudo-science about insomnia, you’d be forgiven for thinking that Argentinian director Gustavo Hernández (responsible for 2010’s scarily innovative The Silent House) is just picking random horror movie material out of a hat at this point. However, Hernández’s new film You Shall Not Sleep (No Dormirás) does a surprisingly effective job of meshing these ideas together into an entertaining, if occasionally inconsistent, psychological thriller.

You Shall Not Sleep stars Eva De Dominici as a promising actress named Bianca who’s selected to compete for the starring role in an experimental new stage play. Placed in an abandoned mental institution, Bianca and the other actors must prepare for their roles by staying awake for an unprecedented amount of time, blurring the lines between fact and fiction. With sleep deprivation taking its toll on her psyche, Bianca begins to suspect that there may be more to this sinister production than meets the eye.

Though the film actually takes place in the 80s, the period setting doesn’t add much to the story other than some superficial set dressing and fashion cues. Nevertheless, the foreboding atmosphere and genuinely chilling narrative make this an engaging mystery that rewards patient viewers, though it’s not without its flaws.

Unfortunately, the experience is somewhat marred down by some clumsy creative decisions (like a handful of lazy jump scares) and a script that needed further polishing. While the narrative mostly works, the second half of the film gets a little convoluted, but it never quite becomes too confusing to be entertaining. Hernández’s creative direction is partly responsible for this, as the film distracts the viewer from most of its narrative flaws with a plethora of compelling characters and memorable visuals.

Speaking of visuals, the cinematography is definitely one of the film’s strongest assets, providing a haunting backdrop for these characters to act and interact while still embracing the movie’s scares. The clever, if somewhat subdued, use of color also stands out even in the film’s darker moments, despite the forsaken setting.

The lead performances are also spectacular, with Dominici remaining a likable main character throughout the film, even avoiding some common horror protagonist pitfalls. However, Belén Rueda steals the show as the manipulative Alma Böhm, who’s organizing the mysterious play and preparing the actors for what’s to come. Ultimately, the competent cast also helps to make up for the flawed script, selling the illusion so earnestly that you can’t help but ignore many of the plot’s inconsistencies.

You Shall Not Sleep may not be a perfect horror experience, but it’s still definitely worth a watch. Hernández manages to weave a compelling tapestry with the film’s central mystery without losing sight of the human element that grounds the story, overcoming nearly all of its flaws. If you’re up for an atmospheric mix of psychological terror, supernatural thrills and the dramatic arts, this should undoubtedly be on your radar.

You Shall Not Sleep screened at the Tribeca Film Festival.