A village that has already decided what happened does not need evidence. It needs a name. In Delusion, the name it reaches for is older than the crime: Phii Pong, the entrail-eating spirit of Isan folklore that towns across northeastern Thailand have invoked for generations to explain the unexplainable and to mark the person no one will stand beside.

That person is Narong, an elderly man whose dementia has erased his ability to account for himself, and this Thai supernatural mystery, arriving on Netflix, watches his daughter Wan, a schoolteacher, fight to defend a father who can no longer defend his own memory. A child has vanished in Chiang Khan, a quiet district in Loei province; a disappearance from a decade earlier stirs with it; and the town, frightened, converges on the one man who cannot say where he was.

Delusion is co-written and directed by Chayan Laoyodtrakool, and it belongs to what has become the most exportable strain of Thai cinema: folk horror that treats belief as social fact rather than superstition. The reference point is The Medium, Banjong Pisanthanakun’s 2021 film that approached Isan shamanism with the patience of a documentary and let dread accumulate through what it was willing to wait for. Thai supernatural storytelling, from Nang Nak to Pee Mak, has long understood the ghost as a community’s shared language, a way of saying together what no one will say alone.

What distinguishes the premise here is the choice of scapegoat. A man with dementia is the perfect suspect for a town that wants certainty: he cannot corroborate, cannot contradict, cannot remember. The Thai title folds the word for illusion into the word for death, and the doubling is the whole design. The delusion is not only the old man’s failing mind. It is the town’s, the collective decision to believe a legend because a legend asks nothing of the people who repeat it.

The overlap the series leans on is not a screenwriter’s conceit. In the northeast, Phi Pop belief has historically read sickness, sleeplessness and mental decline as the marks of possession, the spirit said to inhabit a host and feed on those around it. Dementia, with its confusion and its lost hours, is exactly the kind of affliction that older village logic could file under haunting rather than illness. That is the trap the story sets: the same symptoms that a doctor would call a disease, a frightened neighbor can call proof.

There is a formal wager buried in the doubling, too. A mystery depends on a reliable account of who was where; dementia removes exactly that. Building a whodunit around a suspect who cannot testify to his own innocence turns memory itself into the story’s missing evidence. The audience, like Wan, is asked to trust a man whose mind will not hold still, and the two-timeline structure, a fresh disappearance pulling a buried one back to the surface, means the past the town wants to forget is the very thing the present keeps digging up.

Phi Pop is not invented for the screen. In Isan and across the Lao-speaking northeast it is a living belief, a spirit said to consume the insides of the living, historically invoked to explain sickness and, more quietly, to expel the neighbor who did not fit. Into that closed world the series sends Pete, a police officer from Bangkok, the outsider whose procedural certainty meets a town that answers to a different authority. The friction between the capital’s evidence and the village’s conviction is where the mystery lives, and Chiang Khan, a Mekong-side district better known to tourists for its old wooden shophouses than for anything sinister, gives that friction a specific, unglamorous address.

Natapohn Phornprapha, known to Thai audiences as Taew, carries the series as Wan; Surasak Chaiyaat plays her father, Narong; Jespipat Tilapornputt is Pete, the Bangkok officer; August Vachiravit Paisarnkulwong and Sirani Yankittikan fill out the ensemble. The screenplay is credited to Chayan Laoyodtrakool with Kasidej Sundararjun and Kanokphan Ornrattanasakul, and the casting of a lead as recognizable as Phornprapha in the role of the daughter, rather than the victim or the sleuth-from-outside, signals where the show wants the viewer’s loyalty to sit.

A crime series that hands its detective a ghost is making a promise it has to keep carefully. Solve the mystery with folklore and the case is cheated; dismiss the folklore and the town becomes a set of fools. The stronger path, the one the premise points toward, is to hold both true at once, to let the supernatural be real as belief while the crime stays human, so that the horror is not the spirit but the speed with which frightened people agree on a victim.

That the series exists at global scale says something about where Thai storytelling now sits. For years Thai horror travelled as remake fodder; Shutter was redone in Hollywood before many Western viewers had seen the original. The Medium changed the terms, and streaming finished the job: a folk belief specific to the Lao-speaking northeast can now open, subtitled, in every market on the same morning. Delusion is being asked to travel on the strength of a spirit most of its viewers have never heard of, which is either the risk or the most interesting thing about it. It also fits a pattern: after Hunger and The Whole Truth, Netflix has treated Thai genre filmmaking as a reliable export rather than a novelty, and a regional ghost is now expected to carry a global slot.

Which leaves the question the setup cannot answer, and should not. If a town needs a monster in order to bury a missing child, the truth, when it comes, arrives too late for the man already condemned by it. A verdict can name a culprit. It cannot give Narong back the years he spent as the thing his neighbors were afraid of, and it cannot tell a community that it was cruel rather than merely wrong.

Delusion premieres worldwide on Netflix on 24 September 2026. The first season is in Thai, set in Loei’s Chiang Khan, and it enters a slate that has made Thai supernatural drama one of the platform’s steadiest bets.

Tags: Netflix, folk horror, Chayan Laoyodtrakool, Delusion, mystery series, Natapohn Phornprapha