In the twilight hush of Aranmanaikaadu, Kollimalai, a couple strolls hand in hand, the air thick with forest sounds and distant memories. As night begins to fall, they set up a small camp, and the husband, Ram, heads out to gather firewood. While searching, he stumbles upon a Trishul planted near a towering tree and tries to cut a branch. His effort is stubborn, but eventually he frees the limb—only to discover an iron nail at the point where the branch detached. A strange protrusion seems to push from inside the tree, and suddenly Ram finds he cannot speak or cry out. His wife, sitting a little away with headphones on, remains oblivious to the danger. From the tree’s hollow, a wooden witchcraft poppet slides into view, horrifying him. A chilling, unseen force closes in, and he bursts into a frantic, desperate escape. The wife’s scream pierces the night as the screen cuts to black, leaving their fate hanging in the dark.
Months pass into a new thread of danger and lore. Maari, a forest guard and part‑time guide, is given orders by his boss, Ashok, to lead a group of friends into a restricted forest that sits on the edge of a former government coffee plantation. Before they enter, Maari’s daughter offers him a sacred amulet, a token of protection. The group’s path crosses a rugged driver who stares them down with a calculating, almost malevolent glare. The five friends—Charan [Dev Ramnath], Meena [Gayathrie Shankar], Sethu [Jana Nathan], Charu [Preethi Nedumaran], and Jerry [Mageshwaran]—make their way into the forest, with Maari guiding them. Meena grows increasingly annoyed with Maari’s cautions to tread carefully and respect the forest’s balance, but Maari’s warnings are rooted in a long tradition of local folklore and the livelihoods of villagers who live off the land.
A blocked path to Maayankaadu, a restricted area, becomes the first visible test. They clear the blockage despite Maari’s protests, and the group presses on, provoking their guide’s frustration. The friends press for explanations, and Maari imparts the forest’s deep lore: the local people depend on these woods and honor a delicate balance that should not be disturbed. Their curiosity overrides caution, and the trek continues. Charu becomes preoccupied by a distant noise and wanders toward the cliff’s edge, only to be saved from a fall by Maari. They reach a vantage point, set up a camp, and try to capture a moment in a photograph. Jerry sees a terrifying figure and grows frightened, only to discover that he has become separated from the others.
When Jerry returns to camp, he tells of a force that dragged at his leg, prompting jeers from the rest. To prove their point, Charu and Sethu vow to visit the warning board they had seen, tie a scarf to it, and record the scene on their phone. Maari urges them to stay put, but the duo ignores him and continues their exploration. Deep within the forest, Charu and Sethu discover a dilapidated, haunting house, its air thick with witchcraft dolls and a sense of being watched. Charu, trying to snap a selfie, is suddenly confronted by an unseen figure, and they later find Jerry’s scarf hanging on a tree branch.
As Maari and Charan search for Charu and Sethu at the warning board, they realize the friends have vanished. They rush toward Charu’s scream only to find her lying still—though it’s later revealed to be a prank, and Charan’s anger boils over. When the group returns to the campsite, only Maari, Charan, and Meena remain, and the others appear to be missing. Maari reveals that Charu had mistakenly entered Pechi’s house and recounts the villagers’ fear of Pechi, a woman who learned black magic in Kerala and returned to the forest to perform rites and human sacrifices for demonic powers. A saint’s warning explains that Pechi has become immortal and cannot be killed—only trapped through invocation. With the saint’s help, the villagers manage to bind her soul to a wooden witchcraft poppet and nail it to a tree, a tree that Ram had unknowingly disturbed earlier. The villagers bury Pechi’s physical body nearby and seal her spirit within the restricted zone to shield the village from her darkness.
Even as the group considers leaving, the forest’s terror clings to them. Jerry remembers his missing camera and returns to retrieve it, accompanied by Maari, who is secretly Pechi in disguise. Jerry finds himself inside Pechi’s house, crying out for help. Maari, now revealed, hunts for Jerry, but a camera recording reveals a brutal, unthinkable sight—Ram and his wife’s murder. They race back to the campsite, where Sethu and Meena accuse Maari of killing Jerry. A chase ensues; Maari, protected by the sacred amulet given by the saint, enters the restricted area, while Sethu is slain by Pechi, who has taken on the guise of Jerry. Pechi then kills Charu in front of Charan and Meena. Meena is trapped inside Pechi’s house but remains alive. Maari manages to rescue Charan and Meena and urges them to flee down the hill, insisting that the amulet still guards them from the demon’s reach. As they attempt to escape, Meena is dragged toward the forest’s restricted zone, and Charan, unable to save her, leaves Maari behind to search for her. Charan eventually escapes by clinging to the amulet, which has come loose from Maari’s neck in the struggle.
Charan returns to the campsite to find Maari dead, an agonizing realization that he must endure as he climbs into a car with a rugged man at the wheel who—unbeknownst to Charan—drives him toward Pechi’s lair. Meena sits inside the car as a captive, a stark sign that Pechi and her followers have a bigger plan in motion. It becomes clear that Meena is a bloodline descendant of Pechi; her grandmother awakens when Pechi is released from the tree and reveals that thirteen more human sacrifices are required to satisfy the demon. Teaming up with the thug, Meena lures people into the forest and helps Pechi by delivering fresh victims, even as she eliminates Maari. Back in the present, Charan is bound, while Pechi and Meena prepare to depart the house. The witch’s triumphant appearance signals the completion of six human sacrifices, with seven more still needed in Pechi’s tally. Once that quota is filled, Meena’s own sacrifices would begin, locking the doomed cycle in place. The film closes with the implication that another group will soon enter the forest, drawn by the same lure that claimed the prior trekkers, and the terrifying legacy of Pechi continues to loom over Aranmanaikaadu.
