Set along a harsh, storm-battered coastline, Under Salt Marsh (2026) unfolds in the isolated Welsh town of Morfa Halen, a place where the sea dictates life, memory, and silence. The story begins with a violent coastal storm that tears through the marshlands, exposing not only destruction but a secret the town hoped would remain buried forever.

At the center of the series is Jackie Ellis (Kelly Reilly), a former detective haunted by a case that shattered her career and personal life. Years earlier, the disappearance of a young child left wounds that never healed. When the storm reveals the child’s body, Jackie is forced to face the nightmare she tried to leave behind.

Drawn back into the investigation, Jackie reunites with her former partner, Eric Bull (Rafe Spall), a man burdened by regret and unresolved guilt. Their strained relationship adds emotional weight to the case, as both struggle to balance professional duty with the personal scars left by the past.

As the search for truth deepens, Morfa Halen begins to crack. Beneath the surface of a quiet, close-knit community lies a network of silence, fear, and long-protected lies. The townspeople cling to their secrets, knowing that the truth could tear their world apart.

The natural environment becomes an unforgiving force. Rising tides, relentless rain, and shifting marshland threaten to erase vital evidence, turning time into the detectives’ greatest enemy. Each storm heightens the tension, blurring the line between accident and intention.

Haunted by trauma and driven by obsession, Jackie pushes herself to the brink in her pursuit of justice. The investigation reveals how deeply the town’s hidden crimes are rooted in its history, and how far people will go to protect what they believe is already lost.

Dark, atmospheric, and emotionally intense, Under Salt Marsh unfolds across six gripping episodes where grief, guilt, and deception collide. With powerful performances and a chilling sense of place, the series delivers a haunting mystery in which the sea stands as both witness and judge — and where some truths can never be washed away.