Under Salt Marsh: Kelly Reilly Leads Coastal Crime Thriller For Sky
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Last Updated on November 8, 2025 by Stefanie Hutson
Sky is heading to the Welsh coast with Under Salt Marsh, a six episode crime drama set in the fictional town of Morfa Halen. Created by writer-director Claire Oakley, it follows a former detective whose life is upended when a new tragedy drags an old case back into focus.
What is Under Salt Marsh about?
As a once-in-a-generation storm rolls in from the sea, former detective-turned-teacher Jackie Ellis is trying to rebuild her life in Morfa Halen. Three years earlier, an investigation into the disappearance of her niece destroyed her career and fractured her family.
When Jackie discovers the body of her eight-year-old student on the shore, it reopens the wounds of that cold case and raises the possibility that the two tragedies are connected. Forced back into contact with her estranged police partner, Detective Eric Bull, she’s drawn into an investigation that exposes buried secrets in a close-knit community squeezed between the mountains and the sea.
Who is in the cast?
Kelly Reilly (Yellowstone, Pride & Prejudice) stars as Jackie Ellis, the former detective trying to balance her responsibility to her pupils with the unresolved guilt of the past. Rafe Spall (Trying, Life of Pi) plays Detective Eric Bull, the officer brought back to Morfa Halen to lead the new investigation.
The supporting cast includes Naomi Yang (Chimerica), Jonathan Pryce (The Crown), Dinita Gohil (Treason), Brian Gleeson (Bad Sisters), Kimberley Nixon (Queenie), and Harry Lawtey (Industry).
Additional cast members include Mark Stanley (Happy Valley, The Reckoning), Dino Fetscher (Fool Me Once, Foundation), Lizzie Annis (The Witcher: Blood Origin, Extraordinary), Rhodri Meilir (Pren Ar y Bryn, Craith), and Julian Lewis Jones (House of the Dragon, Wheel of Time).
Behind the scenes
Under Salt Marsh is created by Claire Oakley, whose feature Make Up established her interest in tense, coastal stories. She writes the series alongside Jonathan Harbottle (episodes 3 and 5) and Nikita Lalwani (episode 4). Oakley is the lead director, with Mary Nighy directing episodes 3 and 4.
The series is produced by Little Door Productions in association with Sky Studios, with support from the Welsh Government via Creative Wales. Scott Bassett and Emma Duffy produce, while executive producers include Elwen Rowlands for Little Door Productions, Claire Oakley, Kelly Reilly, and Megan Spanjian for Sky Studios.
Filming took place entirely in Wales, using coastal locations such as Barmouth and Fairbourne to stand in for Morfa Halen’s exposed shoreline.
When and where to watch
Under Salt Marsh will launch on Sky and streaming service NOW in 2026. Sky has not yet announced an international broadcast or streaming partner, so US availability remains unconfirmed for now.
Sky has released a teaser trailer that introduces Jackie, Eric, and the storm-lashed town of Morfa Halen, along with several of the key supporting characters. You can check it out below:
