Kali killed a girl Bhavani as the film starts .Two Russian exorcists who perform exorcism on that girl they succeed in capturing the two spirits. They then trap the spirits in two different nails. Then Raghava Lawrence with his family go to his grandparents 60th marriage celebration. That time Raghava feels hungry , and decides to eat under the tree. The group feels that something was wrong with the place and leave it. The nail drops inside the picnic bag itself. They reach the home. A little later his grandmother shows up and they come face to face with a shadow with spirit, but no one cares about it.
The next day morning all hear some sound. That night Kaviya gets scared by the same shadow from kitchen and her bed room. The grandfather suggests they go to the temple the next day .
When the whole family go there, the Aghoris who were there performing Pujai, sense something. They call forward the family and the head Aghori give them a thirisulam. He asks the family to place the thirisulam on a thulasi maadam, and assures them it would be protecting them. The family do the same. That night, Priya and Dhivya encounter the spirit. Priya is thrown out of the house with the thirisulam landing in front of her(it has lost its powers), indicating that whatever is in their home, is very powerful.
The family go and meet the head Aghori that very night, and the Aghori gives, Raghava's mother, brother and sister-in-law, three voodoo dolls. He asks them to perform some rituals in three different places in their home. The last voodoo doll has to be nailed on the right leg, left leg and head by the three of them.
The next day, the three of them send the kids out and stay late at night to do the rituals. They are terrorized by a horse, cow and lastly encounter the ghost itself, scaring all three to the core. They immediately go and seek the help of the Aghori. The Aghori agrees to follow them to the house. When he enters it alone, the weather changes once again but immediately turns back to normal. The Aghori comes out and says that all is fine.
When the kids come back, that night, Kamakshi (Raghava's sister-in-law) sees the ghost and is convinced that the ghost has not left. Her husband asks her to wait one more night to confirm everything. Priya dreams of kissing Raghava and brings him alone to kiss him, leaving him alone. He then fearing his life, as he is left alone in the dark, hides in the room. There he witnesses paranormal activities surrounding the picnic basket. He opens it and sees the cross nails and is possessed after that. Raghava later brings his cousins to shopping and all the girls buy lipstick, mascara and heels. That night, all of their things are missing and they find Raghava with their stuff, behaving like a girl. They find him terrorizing them later on. When they go to tell his mother, they find him sleeping peacefully.
The next night, after being relieved that all is fine in the house, Kamakshi and her husband are attacked by Raghava(actually the spirit). Together with their daughter, the three sisters, they convince Raghava's mother that the ghost is still there. The three sisters hitch a plan to flirt repeatedly with Raghava to trigger the spirit and to prove their aunt. Their plans get successful and the ghost in Raghava is exposed. It is than revealed that there are two ghosts, one named Rosie and the other her boyfriend, Kaali. All of them get wacked by the ghosts then.
Feeling cheated, they bring the Aghori who falsely told them that the spirit is gone. The Aghori says that he felt pity for the spirit and tells the family the story of Kali and Rosie. Kaali's mother Radha runs an orphanage. She also cares for the slum people. They live as a family. Rosie is from UK, and is also an orphan who stays there. After Kaali mother's death, Kaali takes over her job and dream. He helps all the needy and has an happy life. One day, the Minister's brother Bhavani comes and asks Kaali to take in 100 crore as black money so that they can escape income tax. He also says that Kaali can have 20 crores as a donation for the orphanage. Kaali being a honest man, disagrees. Angered, Bhavani kills one of the handicapped slum man, angering Kaali. He goes to kill Bhavani, which happened in the beginning of the film. Later, Shankar gets revenge by killing Rosie and Kaali, framing it as an accident. He also burns down the orphanage, and kills all the occupants.
Hearing Kaali's story, Raghava's family request Kaali and Rosie to kill Shankar. Kaali and Rosie, go to kill Shankar who escapes into a cemetery. There he reveals that it was his plan to lure him to the place. He brings in the two Russian Exorcists and two others and weaken Kaali and Rosie. The head Aghori arrives with his men and they pray to Goddess Kali, who gives power to Kaali and Rosie. Both of them gain immense power and kill the four Exorcists and finally kills Shankar. In the end, Kaali and Rosie are united and depart.