Crime drama enthusiasts, prepare to mark your calendars—Sky has just dropped a gripping trailer for its upcoming six-part series “Under Salt Marsh,” and it’s already generating serious buzz. Set against the bleak, windswept marshlands of coastal Wales, this slow-burn mystery stars “Yellowstone” powerhouse Kelly Reilly alongside the versatile Rafe Spall, delivering the kind of atmospheric tension that fans of “Broadchurch,” “Happy Valley,” and “The Pembrokeshire Murders” crave. With its rain-lashed visuals, simmering secrets, and a community teetering on the edge as a monstrous storm approaches, this series looks poised to deliver chills, emotional depth, and twists that will keep you glued to the screen.
Premiering on Sky Atlantic and streaming service NOW on January 30, 2026, “Under Salt Marsh” transports viewers to the fictional Welsh town of Morfa Halen—a tight-knit community squeezed between towering mountains and an encroaching sea, where trust runs deep but secrets run deeper. At the heart of the story is Jackie Ellis (Reilly), a former detective who left the force after a devastating unsolved case shattered her career and strained her family ties. Now working as a schoolteacher, Jackie believes she’s found some semblance of peace in this remote haven. That fragile calm is obliterated when she discovers the body of her eight-year-old pupil, Cefin, washed up in the salt marsh, apparently drowned.
This tragic find doesn’t just spark a new investigation; it unearths the ghosts of a three-year-old cold case—the mysterious disappearance of Jackie’s young niece, Nessa, which has haunted the town ever since. As dark clouds gather and a once-in-a-generation storm barrels in from the sea, Jackie is pulled back into the world of detection. Her estranged former police partner, Detective Eric Bull (Spall), arrives to lead the official probe, forcing the pair to confront old wounds, unresolved tensions, and the failures that drove them apart. Convinced the two cases are linked, they race against time to uncover the truth before the raging storm floods the marshlands and washes away crucial evidence forever.
What elevates “Under Salt Marsh” beyond a standard whodunit is its masterful blend of psychological drama and environmental menace. The storm isn’t mere backdrop—it’s a relentless force that mirrors the escalating danger, isolating the town and heightening the paranoia among its residents. Everyone knows everyone in Morfa Halen, yet no one is truly open; loyalties fracture under scrutiny, and long-buried grievances surface like debris in the tide. The series explores themes of grief, guilt, resilience, and the corrosive power of unspoken truths in small communities, where protecting one’s own can mean concealing the unspeakable.
Kelly Reilly, fresh off her iconic run as the fierce Beth Dutton in “Yellowstone,” steps into a role that’s equally compelling but far more introspective. Jackie is a woman haunted by loss, her compassion clashing with a steely determination born from past mistakes. Reilly’s performance in the trailer alone—wide-eyed vulnerability giving way to quiet resolve—hints at another tour de force, showcasing her range in a character who’s free-spirited yet tethered to the land and its sorrows. Opposite her, Rafe Spall brings layered complexity to Eric Bull, a detective returning to a place where he once faltered, his pragmatism masking deeper regrets. Their fractured partnership promises electric tension, laced with unspoken history and mutual reliance.
The supporting ensemble is stacked with talent that adds richness to the town’s web of relationships. Jonathan Pryce lends gravitas in a key role, drawing on his commanding presence from projects like “The Crown.” Naomi Yang, Harry Lawtey (riding high from “Industry”), Dinita Gohil, Brian Gleeson (known for “Bad Sisters”), Kimberley Nixon, and others round out a cast that feels authentically grounded in Welsh life. Local actors and filming in real coastal spots like Barmouth and Fairbourne enhance the immersion, capturing the raw beauty and isolation of the landscape.
Created, written, and primarily directed by Claire Oakley (whose feature debut “Make Up” earned acclaim for its intimate storytelling), “Under Salt Marsh” benefits from a cohesive vision. Oakley co-writes with Jonathan Harbottle and Nikita Lalwani, while Mary Nighy directs select episodes. Produced by Little Door Productions in association with Sky Studios, with support from the Welsh Government, the series boasts cinematic production values—sweeping shots of stormy seas, fog-shrouded marshes, and rain-drenched streets that evoke a palpable sense of dread. The trailer’s moody score and stark imagery amplify the slow-building suspense, promising a visual feast that’s as bleak and beautiful as the Welsh coast itself.
In a genre crowded with coastal mysteries, “Under Salt Marsh” stands out for its emotional authenticity and cultural specificity. It delves into the human cost of tragedy—how grief lingers in a community bound by nature yet divided by silence. The storm serves as a metaphor for buried emotions erupting, forcing confrontations that can’t be postponed. Early glimpses suggest intimate character studies intertwined with procedural elements, where clues emerge not just from forensics but from fractured relationships and half-told stories.
Fans of British crime dramas will recognize the formula perfected here: a picturesque yet oppressive setting, flawed investigators with personal stakes, and a town where innocence is illusory. Yet the series adds fresh layers with its focus on resilience amid vulnerability, and the urgent ticking clock of the approaching catastrophe. The six-episode format is ideal for a taut, bingeable arc—no filler, just escalating stakes leading to what promises to be a devastating climax as the storm hits.
The trailer’s release has already sparked excitement, with viewers praising its haunting atmosphere and the star power of Reilly and Spall. In an era where streaming offers endless options, “Under Salt Marsh” feels tailor-made for those winter nights when you want a mystery that’s dark, poignant, and utterly absorbing. It captures that unmistakable British mood—brooding skies, suppressed emotions, and revelations that hit like thunder.
As the premiere approaches, anticipation is building for what could be one of 2026’s standout dramas. If you’re drawn to stories of shattered lives rebuilt amid chaos, or simply love a thriller where the weather itself feels like a character, this is essential viewing. Clear your schedule come January 30—Morfa Halen’s secrets are about to flood out, and once you dive in, escaping the pull of “Under Salt Marsh” won’t be easy.
