The story begins with District Collector Madhivadhani (Nayanthara), who is struggling with her approval to a higher official (Kitty) and telling a bone-chilling story to him.

A week ago, in Kattoor village, poor people are seen fighting with the police for clean water, sanitation, and the verdict to arrest their cruel landlord. Two boys are seen playing in a river, as their family drags them out and scolds them for going and playing there. The next day, a woman named Sumathi (Sunu Lakshmi) and her 4-year-old daughter Dhanshika (Mahalakshmi) are walking together back home. Sumathi soon learns that Dhanshika went missing and enquires the villagers, who tell her that her daughter fell into a borewell. Sumathi rushes there and faints. The villagers call the police, who in turn alerts Madhivadhani. Madhivadhani and her team rush there to assess the situation but are stopped because there is a deep ditch in the middle of the road, which delays their arrival at the site. Madhivadhani and her team finally arrive but are battered by the journalists and the news media, who criticize Madhivadhani over her late arrival and the negligence of the landlord over the open borewell.

Soon, a camp is set up. Sumathi, her husband Pulenthiran (Ramachandran Durairaj), and her son still await Dhanshika's escape. The police sends down a camera and microphone system so that Madhivadhani can talk with Dhanshika in the borewell. Madhivadhani notices that Dhanshika is not receiving enough oxygen, but the doctors ensure that Dhanshika has enough time to survive. The villagers meanwhile try to rescue Dhanshika on their own but fail every time. The police decides to carry out the "butterfly knot" as they demonstrate to Madhivadhani on a dummy. Madhivadhani alerts the medical team about the consequence of the process that Dhanshika's shoulder might get dislocated, but gives the approval to carry out the process. As the police reach out to Dhanshika with the knot, Dhanshika tries to hold on to the knot, but her arm hurts and she falls back into the borewell. Madhivadhani and the family are distraught over this.

The villagers, angry over the long time taken to rescue Dhanshika and the landlord's negligence, attack the police with stones. Madhivadhani then settles the doubt by telling the villagers that the landlord will get arrested and the child will be rescued. Coincidentally, the landlord gets arrested. Madhivadhani then calls for Captain Maharajan and his team from the Indian Defence Army. Maharajan has an idea: to dig out another horizontal tunnel to get Dhanshika out. Madhivadhani approves it. As Maharajan's team is digging the ground, a crack appears in the ground, which causes all the work to stop immediately. As the day darkens into night, the camera suddenly stops working. As the camera gets fixed, Dhanshika shows no response, which causes Pulenthiran to assume that she is dead. He runs off into the half-dug site as he tries to rescue Dhanshika on his own, thus causing another chaos between the villagers and the police while someone alerts the villagers that Dhanshika is still alive. The family decides to send Muthu (Ramesh Thilaganathan), Dhanshika's brother, to rescue her, which Madhivadhani reluctantly approves. Finally, Dhanshika is rescued alive. Pulenthiran, Sumathi, Muthu, and Dhanshika thank Madhivadhani. Madhivadhani sends Dhanshika to the hospital but emotionally breaks down.

Back in the present, Madhivadhani competes with the higher official and resigns from her post as a district collector. She then decides that she will do something for her people as an ordinary person. The film then ends with a timeline slideshow of incidents of children falling in neglected borewells.