Shock

Vasanth, a stock analyst, and his wife Malini search for a flat in Chennai and finally settle on a high-rise unit on the 12th floor. They move in and begin to build a life together, unaware of the apartment's dark history. They soon notice small unsettling signs in their new home.

The previous occupant, Manju, killed her child and then jumped from the balcony, dying. Malini learns of this incident and becomes fixated on the tragedy, obsessively thinking about it. The discovery casts a shadow over their new home and Malini's behavior begins to change.

Malini's fixation triggers inexplicable experiences that worry Vasanth. He seeks help from a psychiatrist, Dr. Rajan, to determine whether Malini has developed a psychological disorder. The doubt strains their daily life as the couple searches for explanations.

The maid believes Malini is possessed and arranges for an exorcist to intervene. The exorcist spends time with Malini and, through the sessions, learns that Manju's spirit has taken control of her body. The household atmosphere grows tense as spiritual intervention becomes part of the unfolding crisis.

A murder shocks the residents when the watchman is found dead with his head twisted, signaling a sinister force at work. Inspector Paramasivam is assigned to investigate the crime and begins questioning the tenants. The event intensifies the fear that supernatural forces are at play in the building.

Meanwhile, Ajay, another resident, begins acting strangely, fueling suspicion and fear among the tenants. The chaotic atmosphere grows as more unexplained events occur around the high-rise. The case begins to feel personal as neighbors discuss possible connections to the haunting.

Another murder happens around the same building, escalating the sense that the haunting and the rumors are real. Paramasivam continues to investigate, collecting testimonies and pursuing leads. The tension between the supernatural and the human motives becomes clearer.

Through Malini's possession, the truth surfaces: Ajay lusted after Manju and forced himself on her, and Manju jumped to save herself. Malini's body conveys the accusation before the exorcist and others, exposing Ajay's past. The revelation shifts the focus from haunting to human guilt.

Manju's mother arrives, telling her dead daughter's spirit that vengeance cannot be achieved by using Malini as a killer. Manju relinquishes Malini's body, releasing her grip on the possession and turning the focus back to Ajay's wrongdoing. The supernatural threat recedes as truth comes to light.

Inspector Paramasivam confronts Ajay, orders his imprisonment, and tells him to rot in jail. The truth about the assault and the cover-up is laid bare for the others in the building. The community finally sees justice being pursued in the legal system.

After Paramasivam leaves the cell, Ajay encounters Manju's spirit, begs for mercy, and his voice fades as she closes in. The implication is that Manju kills him, ending Ajay's threat and sealing the revenge that began in life.