At noon in the hillstation Sigapurahali, a dark silhouette moves along the edge of the day, and soon after six men are found dead in the tall hora grass by an unseen force. The scene leaves no obvious fingerprints, no murder weapon, and no clear traces of who might be responsible. Officer Palraj leads the on-site investigation, puzzled by the complete absence of evidence yet certain something beyond ordinary crime is at work. The case widens when Constable Kulandaisamy arrives at the SP Office and encounters a woman trying to set herself on fire; calm voices and steady hands from Kulandaisamy and the female constables help quell the crisis, even as ominous chanting and whispering seem to echo in the air.
Chezhiyan [Sundar C] and his family—his wife Regina [Sakshi Chaudhary] and their daughter Diya—arrive in this strange place to start anew. They settle into a rented house, embark on a peaceful family picnic, and watch their faithful dog Danny vanish into the forest, a disappearance that Regina privately dreads as a portent. The couple’s worries are joined by a growing sense of unease as the house itself seems to resist the ordinary: all the windows and furniture are steel, explained by Kulandaisamy as the effect of termites destroying wooden items, leaving behind an eerie, almost mechanical interior.
Diya is drawn to the house’s secrets, discovering a large cloth-covered mirror that seems to stir when she reaches toward it, and a moving cloth-covered mannequin that unsettles her as Regina busies herself with meals. Outside, a window reveals a swarm of crows that suddenly fills the frame, amplifying the sense that something supernatural is watching.
Back at the station, Kulandaisamy reports a troubling telephonic anomaly: a woman cries for help, calling his name, yet the town’s phone lines have been out for days. The next morning, the investigation deepens as Chezhiyan collects clues with Kulandaisamy’s help. Sigarpurhali’s Arabic origin is noted, and the legend of an isolated Arabic magic practitioner—often seen in company with the ragged old man—persists as a possible link to the terror plaguing the town. Despite warnings, Chezhiyan resolves to investigate the practitioner, who is seen praying and chanting but departs when Chezhiyan approaches.
A shift occurs at home when Regina seduces Chezhiyan, and a troubling sequence of missed calls and contradictory movements around their house suggest a dangerous deception at play. A call from Regina’s number after the supposed intimacy reveals that, while Chezhiyan was physically with Regina, the landline at home had recorded a panic call. He traces the inconsistency to a hidden intruder, and soon confronts the magician outside the house. The magician warns that a dark figure, named Sila, has entered Chezhiyan’s home and that she is neither human nor of this world. To keep her at bay, the magician must chant prayers a precise number of times before dawn.
Regina and Diya’s sequence of terrifying encounters intensifies: Diya experiences a vision of Sila in black as Regina goes about school runs and whispers of motherly love clash with an escalating fear. The hill’s power seems to surge as Chezhiyan seeks spiritual guidance from a Muslim priest to determine prayer times, while Regina rushes to hospital with Diya after the girl develops a disturbing rash. The scenes at the hospital blend dread with the ordinary as a phone call reaches Chezhiyan while Regina continues to struggle with Diya’s condition, forcing the family to stay under medical care as they navigate the mystery inside their home.
Inside the house, Sila watches, moves, and tests Chezhiyan’s scent by tracking his leather jacket. The tension crescendos at dinner, where silence hangs heavy; Diya’s scream breaks the quiet, and the couple discovers her cowering in fear as Sila lurks near the windows, with the ragged old man chanting and sprinkling water around the perimeter. When Chezhiyan expels the old man, Sila clings to the windowsill, and the old man reveals that the magician’s prayers might hold Sila at bay only until dawn—and that a more dangerous force has taken hold.
As dawn approaches, the magician is drawn back into danger: a demon in white haunts the house, and a chain of events leads to the magician’s murder in the forest, his body found impaled on a tree and consumed by termites. The forensic team uncovers two blood samples—one the magician’s, the other belonging to a rare Bombay Blood group found only in Maharashtra and Gujarat—pointing toward a specific Arabic-linked suspect. A portrait of a Gujarati woman, bearing an unusual Arabic signature, becomes the focal point of the case, and Chezhiyan compares it to Diya’s own knowledge and memory, realizing the truth lies closer than expected.
Diya’s recognition of the woman in the photo confirms the link to Sila, and Regina and Diya are moved to another house while Kulandai helps swap sheets—the same sheets from the night Chezhiyan allegedly shared a moment with Sila. The police dog is brought in to track Sila’s hideout in the forest, and the investigation expands to connect a web of Arabic origins, the hill’s southern location, and a Quranic verse search that leads to a Muslim priest. The priest explains Sila as an evil Jinn who, along with five sisters, can only be changed back when humans strike at their weakest moment; the five Silas are said to have incarnated as hora grass, termite, fish, dog, and snake, with one human child surviving Gujarat’s earthquake to resist transformation.
From this revelation, a Gujarati-born Silas’ sister emerges as the living threat, and Chezhiyan races to save Regina and Diya. In a final confrontation, Chezhiyan confronts Sila and, with the priest’s guidance, brings about her defeat, ending the terror that had plagued the hill station. The resolution binds the family together and restores a fragile calm to Sigapurahali, leaving the community to reckon with the strange, enduring forces that once walked its woods and walls.
