After Priya and her daughter Aishu relocate to an apartment in Chennai, Priya finds something strange and unusual about the 6th floor in the apartment. Later, when Priya and Aishu go to the supermarket, Priya loses her wallet. The next day, in an unusual way, Priya finds Aishu missing.

Priya panics and along with Santosh goes desperately searching for Aishu. Priya while searching for Aishu in the park meets a strange young girl. Priya ends up losing the girl and goes to the police station and informs the inspector that the young girl is the one who is hiding Aishu. The inspector does not believe her. Priya leaves back home and finds Aishu there - which is actually revealed to be a dream. Priya thinks - Flashback of Ram telling her to always search properly and that she will find something. Priya then goes back to the park and enters illegally and gets caught by the police who warns her not to do this again. Priya gets back to the apartment and spots a little girl on the 6th floor standing in front of a door. Priya then breaks into the house and finds shocking details.

The inspector comes to Priya's apartment after the neighbours complain about a door being broken and investigate. Priya tells the inspector about what she finds at the house. The police start their investigation from their side. Santosh decides to help Priya in finding Aishu and goes looking for details about the girl. Santosh and Priya go to the writer's house who was the first part of that missing girl's investigation give them a lead on what happened and about Loudersamy who was the inspector who was investigating the case back then. Santosh and Priya go to Loudersamy's house and find more details about the girl and her family.

Priya and Santosh go through the evidence box from Loudersamy's daughter. They find a tape which reveals few details of Manju's family. Poorna and Santosh go the asylum in search of Balu. Priya gets home and sees the video again when the old lady from the lift comes in and is shocked to see the video and tells them about the family. Poorna gets reminded of Aishu and cuts to flashbacks when Aishu was born. Priya then decides to bring Balu home and recreates the birthday of Manju from the video to rekindle Balu's memory. Balu on seeing the decoration gets reminded of that day and runs away. Poorna feels helpless.

Priya goes in search of Balu. Priya finds Balu outside a house throwing stones at it. Priya gets into the house and finds a lady sitting in a wheelchair emotionless. Priya screams and cries asking where her daughter is. Priya starts searching for the house and then finds a room filled with kids toys and clothes. Priya then gets into a room with frozen bodies of kids. Priya panics and starts searching for Aishu when the villain spots her and knocks her unconscious after a lot of struggle Priya with the help of Balu and Santosh rescues Aishu.