Gopi, a dedicated dubbing artist, is kidnapped by the henchmen of a blind, wealthy man and is beaten as the boss orders him to lead the way to Kunju Thanni Forest. Gopi agrees, hoping to secure the promised money, and guides them into the forest where a chilling sight soon greets him—a zombie lurking in the shadows.
Years pass, and a disparate group of strangers makes their way to the Kunju Thanni Forest, planning to end their lives by leaping from a cliff. As they share the personal reasons driving their desperation, they encounter Mahesh, known as Poraali Mahesh, who offers them a drink and steps into the role of their reluctant guide. He listens to their stories, and the group begins to bond in the face of their shared fate.
Mahesh opens up about his own past, including brushes with the law and a narrow escape from jail, painting a portrait of a man who has seen hard times and learned to rely on wit and chance. The mood shifts when a curious twist of fate leads one of the men, Arumai Nayagam, to stumble into a laboratory filled with zombies, amplifying the fear that grips the group.
Amid the terror, a young woman named Sathya appears and rescues them from the roving undead. Mahesh finds himself drawn to her, and she quickly asserts herself as more than a savior—she becomes the focal point of the group’s fledgling dynamics. Sathya begins to hand out buns to the men, and after they eat, they fall asleep. When they awaken, they discover they are all bound with ropes, a sign that Sathya’s interest in zombie research may be driving her actions. As the zombies close in, Mahesh prays, hoping for a miracle, and Sathya decides to save them, stepping into a dangerous role to keep them alive.
Tragically, Sathya is bitten during the rescue, forcing Mahesh and his companions to carry her to a safe place—the home of Sathya herself. On the way, Parthasarathy sacrifices his life to shield Mahesh and Sathya from the encroaching danger. In a tense moment, Sathya injects herself with an antidote and begins to reveal her past, laying bare the tangled history behind her actions.
Her story centers on her father, Rohit Sharma, a scientist who dreamed of transcending death through a project named Project Cthulhu. Rohit’s research creates a virus that births zombies, and he himself is bitten by the infection. Sathya saves her father from the zombie threat, but the virus ultimately animates Rohit’s body into a zombie persona associated with the infamous “Hitler.” The flashback closes as the group exits the house and encounters Gopi once more, the same dubbing artist they met at the forest’s edge.
As the truth comes to light, Arumai Nayagam urges Mahesh to propose to Sathya when she is alone, and he gathers courage to do so. But the moment is interrupted when Hitler’s zombie army captures Sathya and drags her to Hitler’s residence, a revelation that shocks Mahesh and his friends. Gopi explains that Hitler believes Sathya is his wife because of her striking resemblance to his former partner, adding a layer of danger to their mission.
Refusing to abandon Sathya, Mahesh and his companions devise a plan to outsmart the zombie horde and stage a daring rescue. They manage to save Sathya by exploiting a calculated ruse that catches Hitler’s forces off guard. In the end, through danger, courage, and a shared resolve, Mahesh and Sathya find their way to a hopeful future together.
