Ivan Kavanagh’s The Canal spooked audiences with an atmospheric, ghostly mystery when a film archivist discovered a film reel of a murder that took place in his home. The filmmaker reinvigorated a classic haunted tale with unnerving sound design, expertly crafted scares, and a steady escalation of suspense to leave a lasting, chilling impression. With his latest, Son, Kavanagh applies that same skillset to a familiar setup, infusing refreshing style and dread to create a powerfully discomforting depiction of just how far a mother would go for her son.

Andi Matichak (2018’s Halloween) stars as Laura, the single mother of an eight-year-old son, David (Luke David Blumm). Their everyday life gets upended one night when a group of strangers shows up in David’s room. The detectives who answer her call don’t suspect foul play, but detective Paul (Emile Hirsch) stays to help when David falls violently ill with a mysterious affliction that stumps his doctors. Laura’s convinced it’s related to the cult she fled from long ago and discovers how far she’s willing to go to protect him from her dark past.

Everything about the premise sounds familiar. It centers on a woman still looking over her shoulder in paranoia, keeping a perpetual eye out for signs that her past has caught up to her. A desperate mother is willing to pay any price to keep her child healthy and safe. The genre has long explored both the depths of a mother’s love and the psychological toll of a cult’s hold. Writer/Director Kavanagh combines them both into one central mystery surrounding David’s increasingly dire condition. It’s less about the destination here, but rather the captivating journey.

Much like The Canal, Son slowly ramps up the intensity, building toward a climax that sticks with you. As the puzzle pieces start to click into place, it paints an insidious picture made more powerful by its simplicity. Unlike Kavanagh’s previous genre effort, Son’s visual style is much more rooted in the present, full of vivid neons and bold hues to contrast the mounting darkness in small-town America. Once again, Kavanagh displays a knack for building an eerie atmosphere through sound, imagery, and implied horrors. It’s often what’s in the stillness that brings the terror. The filmmaker doesn’t rely on jump scares to build the fear, which means that the few he does employ pack a mean punch.

Framed entirely from Laura’s perspective, Matichak does the heavy lifting as the spiraling mother on the run. She proves more than capable of carrying a film on her own. Laura’s arc as the pure, doting mother to one willing to subject herself to shocking evil is plausible thanks to Matichak’s grounded portrayal. The character’s effortless affability makes it easy to follow along on her gradual downward spiral. It helps that David is refreshingly played as a sweet innocent, rather than your conventional creepy horror kid. This is an endearing pair with a rooting interest. Hirsch is less present and amiable enough; he’s there to help increase the stakes when necessary.

Son may not win points for narrative originality, but it makes up for that with a distinct visual style and palpable dread. It’s not what happens that makes Son work so well, but how Kavanagh once again delivers potent chills and an ominous atmosphere. Matichak imbues a straightforward earnestness that gives emotional stakes. For a movie that hinges on a ferocious mother’s determination to save her child, she brings Laura right up to evil’s edge without ever losing authenticity along the way, culminating in an unforgettable conclusion that leaves a mark.

Son releases on digital, VOD, and in theaters on March 5, 2021.