Masilamani is a suspect in a murder case, and the police take him into custody for questioning. The film opens inside a police station with a tense interrogation led by the deputy commissioner, while other officers suggest the usual hard-edged methods. Yet the deputy commissioner resists those techniques because there is already a letter from the Human Rights Commission watching over the case. As the questioning unfolds, the audience gradually learns that Masilamani's family life is strained: his son requires constant medication, and even with treatment, the boy’s life is expected to be short. Masilamani proves adept at outsmarting his interviewers, and to assist the process, a female psychologist is brought in to help crack the case. It is revealed early on that Masilamani’s wife is dead, and her body sits in the mortuary.
As the interrogation deepens, Masilamani begins to confess not only to the single murder he’s accused of but to two more, all executed with the same disturbing modus operandi. He reveals that he is married to Usha, and they share a child who is gravely ill. He describes a fractured marriage in which his wife engaged in affairs, a situation she claims she pursued to fund their son’s medical needs. She explains that she did it for money, and in a desperate moment Masilamani contemplates ending those entanglements since he cannot fight the powerful men involved through legal means. The killer’s signature method involves leaving a single slipper, a size 7, at each crime scene.
Dr. Surya, the psychologist, becomes part of the investigation as Masilamani’s confessions unfold. His narrative paints a picture of a wife who reluctantly admits to the affairs, blaming the blackmail from men who possess a nude video of her. However, Masilamani’s sense of justice drives him to kill the men involved, and the trail of murders grows with the same distinctive single slipper left beside each corpse. When Usha discovers the other slipper pair and realizes Masilamani is behind the killings, she erupts in panic and arranges for henchmen to murder him. The twist comes when it’s revealed that Usha’s affairs were not solely driven by blackmail; she had willingly slept with those men. In a cruel turn of fate, Usha dies in a road accident while the henchman escapes, only for it to later emerge that the henchman himself is murdered using the same MO.
Masilamani persists in his revenge, eliminating the remaining men who had affairs with his wife and continuing to leave a single slipper of size 7 at each scene. The investigation uncovers a much larger corruption: years earlier, the current head of police personnel aided a powerful minister in covering up his brother’s murder, an act that left a slipper beside the body as a chilling reminder. Masilamani not only has proof of that earlier crime but also an undeniable link between the minister, the cop, and the MO that ties all the murders together. He uses this knowledge to threaten that he will expose the entire scandal if he is not released. Faced with the potential truth spilling out and the danger it poses to powerful figures, the police choose to let Masilamani go.
The film concludes with Masilamani walking out of the police station, his young son in his arms, and a somber sense of closure as he accepts his wife’s death and the harsh realities surrounding the case.
