Yellowstone favourite stars in first look at new Welsh drama about "unspeakable crime"

Sky has released the first teaser trailer and a batch of new images for Under Salt Marsh, a haunting new Welsh-set crime drama starring Yellowstone’s Kelly Reilly.

The Sky Original series follows former detective Jackie Ellis (Reilly), who has swapped policing for teaching after a devastating case shattered her career and family life.

But when a violent storm hits the fictional coastal town of Morfa Halen, Jackie makes a discovery that forces her to confront the past – and an “unspeakable crime” buried within the community.

Rafe Spall (Trying, Life of Pi) also stars as Jackie’s estranged former partner, Detective Eric Bull. The pair are reluctantly reunited as the investigation reopens, exposing old wounds and long-buried secrets before the incoming storm wipes away the evidence for good.

You can watch the Under Salt Marsh teaser below:

Created, written and directed by Claire Oakley, the six-part drama promises a brooding mix of mystery and emotion, exploring grief, guilt and the corrosive effects of secrecy in a close-knit town.

The cast also features Jonathan Pryce (The Crown), Naomi Yang (Chimerica), Dinita Gohil (Treason), Brian Gleeson (Bad Sisters), Kimberley Nixon (Queenie) and Harry Lawtey (Industry), with Mark Stanley, Dino Fetscher, Lizzie Annis, Rhodri Meilir and Julian Lewis Jones rounding out the ensemble.

Series lead Reilly is best known to audiences for her role as the sharp-tongued, fiercely loyal Beth Dutton in Paramount’s hit western Yellowstone, where she starred opposite Kevin Costner.

Reilly and Cole Hauser are expected to reprise their fan-favourite roles as Beth and Rip Wheeler in a follow-up series currently titled The Dutton Ranch.

Under Salt Marsh will air on Sky and streaming service NOW in 2026.

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