Puducherry-based Krish, Prashanth, is an ambitious pianist who fakes blindness as an experiment to sharpen his piano skills. While crossing a street, he is knocked over by Julie; she tends to him, and her growing admiration for his talent helps spark a romance. Krish wears opaque lenses to practice, but after meeting Julie, he is tempted to look at her. He stops wearing the lenses and simply pretends to be blind.
At a diner, a retired actor, Karthick, Karthik Muthuraman, notices Krish and invites him to perform for his wedding anniversary. Krish arrives at Karthick's flat, and Karthick's wife Simi Rekha Suresh opens the door. To avoid a nosy neighbour, D'Susa, who is watching and sees that Krish is blind, Simi lets Krish inside to play the piano. Krish sees Karthick's corpse nearby but has to feign ignorance and continue to play. He also sees Manohar, Simi's paramour, hiding in the bathroom. Simi and Manohar clean the crime scene and stuff the corpse into a suitcase while Krish plays.
Krish tries to report the murder to sub-inspector Bala, but is dissuaded when he discovers that Manohar works at the same police station. At Karthick's funeral, D'Susa tells Bala about seeing an unknown man (Manohar) going to Karthick's flat the day of his murder. Simi pushes D'Susa off the ledge of their apartment. Krish happens to see the murder when he arrives to give piano lessons to Karthick's daughter, Sanjana, but is forced to continue feigning blindness. Simi goes to Krish's house and hands him prasada as Krish makes coffee for them. After poisoning his coffee, she observes him carefully and busts his act after he spills the coffee on purpose. Krish says he will leave for London and keep Simi's secret, but falls unconscious.
Kappes, the neighbour's son, has recorded a video of Krish fully able to see and shows it to Julie. As she arrives, Simi arranges things to look like she and Krish had slept together. Anguished, Julie leaves Krish. On regaining consciousness, he realises that he has been blinded from the prasada. Manohar comes to Krish's house to kill him. Krish barely escapes, but faints after hitting a telephone pole.
Krish wakes up in an illegal organ harvesting clinic. Dr. Sami and his assistants Murali and Sarasu decide to spare Krish when he reveals he has information that will make them millions. They kidnap Simi, stage a suicide scene, and blackmail Manohar. However, Murali and Sarasu double-cross Krish, tie him up with Simi, and plan to take the money themselves. Murali takes the money from Manohar, but is wounded when escaping from him. Manohar becomes trapped in an elevator, and once he escapes, Sarasu knocks him out. While Murali is hospitalised, Sarasu finds the money to be counterfeit.
Simi helps Krish free himself and he removes Simi's blindfold. While he is trying to find an escape for both of them, Simi frees herself and attacks him. Sami enters; after a brief fight, he and Krish knock Simi out, tie her up in the boot of a car, and drive away. Sami reveals that Simi has a rare blood type and that her organs would sell for millions; he also plans to use her corneas to restore Krish's sight.
Two years later, in London, Julie finds Krish. He tells her the whole story, explaining that after he and Sami drove away, Simi awoke and began making noise. Sami stopped the car to sedate her again, but she overpowered him and seized the wheel. Krish, thinking Sami was still driving, tried to persuade him to release Simi. She revealed herself, dropped Krish off and tried to run him over. A nearby hunter, trying to shoot a hare, missed his shot, causing the hare to jump and hit the windshield; Simi lost control of the car and died when the car crashed.
After listening to Krish's story, Julie tells him that he should have accepted Sami's offer, and Krish quietly walks away. After a while, he uses his cane to knock a can out of his path.
