In a streaming landscape overflowing with predictable slashers and jump-scare-heavy horrors, The Block Island Sound stands out as a boldly unconventional entry that’s proving deeply divisive among Netflix audiences. This 2020 indie sci-fi horror thriller, directed by brothers Kevin and Matthew McManus, has resurfaced with renewed buzz, earning descriptions like “viciously uncomfortable,” “weird but brilliant,” and “impossible to forget.” Boasting an impressive 90% critic score on Rotten Tomatoes, the film challenges viewers with its slow-burning psychological tension, atmospheric dread, and a jaw-dropping final twist that reframes the entire narrative. While some hail it as a thought-provoking gem that dares to be different, others find its deliberate pacing and ambiguity frustrating, even admitting they struggled to finish it. For those seeking a horror experience that lingers long after the credits, this enigmatic tale of an ominous oceanic force is a haunting, unforgettable watch.
Set on the remote and windswept Block Island off the coast of Rhode Island, the story unfolds against a backdrop of desolate beaches, foggy seas, and a tight-knit community where everyone knows everyone’s business—or thinks they do. The plot begins innocently enough but quickly descends into unease. Local fisherman Tom Lynch wakes up disoriented on his boat, surrounded by chaos, with no memory of how he got there. Strange phenomena plague the island: massive die-offs of fish washing ashore in tons, birds plummeting from the sky, and residents experiencing blackouts, hallucinations, and erratic behavior. Tom, a grizzled lifelong islander, starts acting increasingly bizarre—violent outbursts, midnight boat trips, and cryptic mutterings—putting his family in unwitting danger.
His adult children become drawn into the mystery. Son Harry, who lives with Tom and works on the family boat, notices his father’s decline firsthand and begins experiencing similar lapses himself. Harry’s estranged sister Audry, a marine biologist working for the Environmental Protection Agency, arrives on the island with her young daughter Emily to investigate the ecological anomalies. Accompanied by her colleague Paul, Audry’s scientific mindset clashes with the growing paranoia, as she dismisses supernatural explanations in favor of rational ones like environmental toxins or parasites. Meanwhile, Harry’s conspiracy-obsessed friend Dale feeds him wild theories about government experiments, mind-controlling entities, and global patterns of unexplained events.
The narrative masterfully builds a sense of creeping dread rather than relying on gore or monsters. Much of the horror stems from psychological unraveling: characters zoning out mid-conversation, waking up in strange places, or seeing visions of the dead. The island’s isolation amplifies the paranoia—cell service is spotty, ferries are infrequent, and the off-season emptiness turns familiar locales like diners and bars into eerie voids. Sound design plays a crucial role, with an unrelenting hum or drone underscoring scenes, creating a disorienting, de-realizing effect that mirrors the characters’ mental fragility.
As the story progresses, the focus shifts to family dynamics strained by grief, resentment, and unspoken traumas. Tom’s disappearance and presumed death force Harry and Audry to confront their fractured sibling relationship, while Emily’s innocence provides poignant contrast to the escalating chaos. The film explores themes of inherited mental illness, environmental collapse, and human arrogance toward nature, blending them with Lovecraftian cosmic horror influences—vast, indifferent forces beyond comprehension lurking just out of sight.
The climax delivers visceral intensity: abductions, frantic chases, and desperate attempts to resist an invisible pull. But it’s the final revelation that truly shocks, delivered through a chilling voiceover echoing Audry’s earlier explanation to Emily about why scientists capture and study fish. The twist posits that humanity isn’t at the apex of intelligence; instead, we’re specimens in a larger experiment, observed and sampled by superior beings using methods eerily similar to our own. This ironic parallel—humans as the “fish” being tagged, dissected, and released for further study—reframes the entire film as an allegory for scientific ethics, ecological hubris, and our place in the universe. It’s a mind-boggling pivot that transforms personal tragedy into existential terror, leaving viewers unsettled and questioning reality.
What makes The Block Island Sound so polarizing is its refusal to spoon-feed answers or deliver conventional payoffs. It prioritizes atmosphere and implication over explicit reveals, evoking classics like The Wicker Man or Invasion of the Body Snatchers while nodding to H.P. Lovecraft’s unknowable eldritch horrors. The lack of on-screen monsters or heavy effects forces reliance on suggestion, making the dread more intimate and psychological. For patient viewers, this yields a richly rewarding experience; for others, it feels slow and unresolved.
The performances anchor the film’s emotional core, elevating it beyond typical indie horror. Chris Sheffield stars as Harry, the troubled everyman thrust into the role of unreliable protagonist. Known from The Maze Runner series, Sheffield brings a raw vulnerability to Harry—a directionless fisherman grappling with grief, isolation, and creeping madness. His portrayal of confusion turning to desperation is nuanced, making Harry’s blackouts and outbursts feel authentically harrowing rather than performative.
Michaela McManus shines as Audry, the rational outsider whose scientific detachment crumbles under mounting evidence. As the directors’ real-life sister, her casting adds familial authenticity, and she delivers a grounded, empathetic performance that grounds the film’s more outlandish elements. Audry’s journey from skeptic to victim provides the story’s intellectual heartbeat, with McManus conveying quiet strength and maternal protectiveness amid growing terror.
Neville Archambault is unforgettable as Tom, the enigmatic father whose early strange behavior sets the tone. His weathered, taciturn presence evokes a lifetime of hard island living, and his cryptic episodes—mumbling incoherently or staring blankly at the sea—are chillingly effective. Though his screen time is limited, Archambault’s intensity lingers, embodying the film’s theme of unseen forces eroding the mind.
Young Matilda Lawler, as Emily, brings heartbreaking innocence, her wide-eyed curiosity contrasting the adults’ paranoia. Supporting roles add texture: Ryan O’Flanagan as the affable but out-of-depth Paul, Heidi Niedermeyer as another sibling, and Willie C. Carpenter as the sympathetic local chief. A standout cameo comes from Jim Cummings (The Wolf of Snow Hollow) as Dale, the conspiracy theorist whose manic rants about parasites and extraterrestrial influences inject dark humor and foreshadowing.
The McManus brothers’ direction—filmed on location for authentic bleakness—excels in capturing off-season desolation: empty beaches, overcast skies, and crashing waves that feel both beautiful and menacing. Their background in clever, twisty storytelling (from Netflix’s American Vandal) shines through in the script’s misdirections and layered metaphors.
Ultimately, The Block Island Sound isn’t for casual viewing—it’s a challenging, thought-provoking horror that demands attention and rewards with profound unease. Its high critical praise stems from bold originality and thematic depth, while audience division reflects differing tolerances for ambiguity. If you’re tired of formulaic frights and crave something viciously uncomfortable that probes the horrors of the unknown—both cosmic and human—this Netflix hidden gem will haunt you in ways few films manage.
