Under Salt Marsh Episode 5 recap: Jackie questions Osian about his afternoon with Cefin

Episode 5 of Under Salt Marsh brings Jackie into a tense, long-awaited confrontation with Osian, compelling both of them to finally address what truly transpired that afternoon with Cefin. As buried emotions resurface and unanswered questions demand clarity, the encounter pushes the narrative into deeper, more unsettling territory. Was Osian’s intention genuinely to offer an apology and make amends, or is there a far more troubling truth he is still determined to keep hidden?

Jackie does not buy his answers, and neither should we. Episode 5 makes it clear that almost every adult on the island is protecting themselves first, and while August’s death shakes up the town, Jackie focuses on the movements and on all of the lies.

Episode 5 of the drama is less about grief and more about the pressure that comes with it because, for now, the secrets are riskier, and nobody might walk away clean.

Spoiler Warnings for: Episode 5 of Under Salt Marsh

Under Salt Marsh Episode 5 recap:

August’s death causes panic on the island

Under Salt Marsh Episode 5 begins right after August’s body is pulled from the water. Bull and Jackie bring him back to shore and store the body to stop further damage while questions pile up.

August’s death - Under Salt Marsh, Episode 5. (Source: Sky TV)

Nobody is fully convinced this was a simple drowning. There are strong hints that August was being paid to stay quiet about the waste problem and what happened to Nessa, and these hints point to a suspicious death.

The police now need answers about who was paying him and what exactly he knew. Jackie starts going through evidence, but gets warned to stay out of the investigation. She nearly spots a DNA match linking Dylan to the case, but misses it for now. The storm outside is getting worse, too, with rising sea levels pushing everyone into survival mode.

Elsewhere, Under Salt Marsh Episode 5 had the town preparing for evacuation. People argue about where to go while strong winds and flooding threaten everything. Some want to head to the farm, others choose the woods, creating more confusion.

The caravan fire reveals August’s truth

While everyone is still dealing with August’s death, things get even darker when his caravan is suddenly set on fire. Bull and Jess rush to the scene after spotting smoke in the hills. It becomes clear right away that this is not an accident and that someone actually wanted whatever was inside that caravan gone for good.

The caravan fire - Under Salt Marsh, Episode 5. (Source: Sky TV)

Even with the flames, Bull manages to find something buried nearby. A bag full of documents. August had been collecting proof about the landfill and the waste being moved around the island. He also knew more about Nessa than anyone realized. These papers suggest he was trying to warn the council before things went too far.

Victor later brings up CCTV footage, and Ned Bevan is seen near the caravan, but he is not alone. Someone else sets the fire. The individual appears to be a man with a heavier build. Although there is available footage of the person in question, the visual quality and clarity are insufficient to allow for a definitive or reliable identification.

Jackie confronts Osian about Cefin

One of the most intense scenes in Under Salt Marsh Episode 5 comes when Jackie goes to speak with Osian. She wants the truth about that afternoon involving Cefin. Osian admits he went looking for the boy after grabbing him earlier and wanted to apologize. He never told the police because he feared being blamed for murder.

Jackie confronts Osian - Under Salt Marsh, Episode 5. (Source: Sky TV)

Osian explains that he followed Cefin after school and eventually caught up with him and James. The boys got scared and ran when they saw him. They headed down the salt path near where Cefin’s body was later found. Osian claims he then went home and that James was with him afterward, which gives him partial backup.

This conversation does not fully clear him. Instead, it opens more bridges in the timeline. Jackie senses that something is still missing. The show uses this moment to push the mystery further without giving clean answers. Osian might be telling part of the truth, but not everything.

Secrets come falling apart as Ned tries to make an escape

As the storm worsens, the truth about Nessa finally begins to come out in the open. Solomon admits that when Ned first found Nessa’s body, August was with him. They realized she was already dead, and they decided to bury her instead of coming forward and reporting the death because they believed they were protecting the family and the farm.

Ned tries to escape - Under Salt Marsh, Episode 5. (Source: Sky TV)

This also explains Solomon’s earlier confession. He had been covering for Ned the entire time. After being confronted about Nessa’s death, Ned decides to flee the island. He believes August’s death is connected and fears he will be next.

Jackie rushes to the dock to stop him. Ned tells his side of the story, but panics when she tries to hold him there. He shoves her and escapes, leaving Jackie injured. Meanwhile, Bull also reveals that he has been hiding evidence that links Dylan to Cefin, trying to protect Jackie from the fallout.

Under Salt Marsh Episode 5 ends with the investigation cracked wide open but far from solved. Osian’s version of events does not sit right. Ned runs, and the truth about Nessa finally comes out in full.

Jackie pushes too hard and pays for it, while Bull admits he has been hiding key evidence. The storm outside mirrors the mess inside the case. By the final few minutes of the episode, the island feels smaller than ever.

Episode 5 makes it obvious that the truth isn’t about to be just buried anymore. Everything that the people have previously tried to hide is slowly coming apart, and it’s getting harder for anyone on the island to keep their secrets straight.