The film begins with an aged man entering a graveyard to lay flowers on somebody's grave. He hears the noise of someone struggling in a coffin nearby. He digs into that place and opens the coffin. To his utmost surprise, he discovers a girl buried alive in the coffin. He takes the girl and admits her to the hospital. Inspector Anton Varghese (Siddharth Kher), the officer-in-charge of the case, tells the doctor to let him know as soon as she regains consciousness and asks one of his officers to stay alert in case the girl is attacked again. Interestingly, that very officer turns out to be a dishonest one and calls an anonymous person informing him of the girl being alive. He, then, secretly enters her cabin for a second attempt to kill her and this time too, by suffocation. He presses a pillow on her face, but she manages to press the alarm button. This causes the nurse to rush to her cabin. The officer goes out of the cabin pretending to be unaware of the attack. Now, that the girl has become conscious, the doctor calls Inspector Anton. When Anton, along with the doctor, goes into her cabin, they find her missing. Anton, frustrated, sends his officers to look for her and himself goes to the ground floor to meet the dean. While he is waiting for the lift, he remembers the monitor in her cabin still working meaning that the girl was right there when they entered. He goes back to the cabin, but the girl had already escaped. She crawls her way to the storeroom.
The girl is revealed to be Sonika (Surveen Chawla) and is the mistress of a powerful and influential political leader Mandar Mhatre (Sushant Singh). Sonika is a photography student. Sonika is kept isolated and tortured by Mandar. She reluctantly finds comfort in her college friend Akshay Bedi (Jay Bhanushali) who secretly loves her. They both fall in love, but Sonika is helpless since she can't tell Akshay about her being the mistress of Mandar. Akshay gets to know the truth and comforts her. They both move to a different home and decide to spend their lives together. They declare their love and have sex. Sonika is happy and finds some hope that she will be free from the torture that she would tolerate. Mandar tries to find Sonika but she is nowhere to be found in her house. Later on, he gets to know that she has eloped with her lover.
Mandar and his men reach Akshay's house and attack him. Sonika cries and pleads Mandar to leave Akshay but he refuses to. Mandar's men kill Akshay by tying him to a rope and throwing him in a lake in a car. Mandar also buries Sonika alive in a coffin. After she is rescued, she vows to exact vengeance upon Mandar for murdering Akshay and for herself. She at first kills the police officer who tried to kill her. Then she writes a diary describing her torture. She dives into the same lake and puts it in the car. She then kills one of the three men who was involved along with Mandar in killing Akshay. After that, she informs Anton about Akshay's dead body. However, even though Anton gets hold of Akshay and through the diary Mandar makes it look that Sonika killed Akshay. Sonika then again manages to put everything in the right order and kills another man of Mandar involved with Mandar in killing Akshay. Then Sonika teams up with Mandar's arrival and gets hold of the third man of Mandar involved in killing Akshay. However, all of a sudden Mandar himself kills that person.
It is revealed that the arch-rival had become the partner after Mandar offered to share his seats with him in the election. Mandar makes it look that Sonika did it and thus the police officer catch her. However, she manages to escape with Anton's help. Then Sonika kills Mandar with Mandar's wife's help (who came to know about Mandar's wrongdoing accidentally). Next day, Anton provides a locked house for Sonika to live there in the safety, giving her the new identity of 'Veronica', knowing that no-one would even contemplate that a fugitive is hiding in a safe house provided to her by the very officer leading the manhunt to find her.