On a stormy night in Bangalore, a large tree branch crashes through the roof of an apartment, and the woman inspecting the outhouse ends up in the hospital. In a different town, Sanjana and her husband, Kabir, quarrel about not being able to celebrate her birthday together, a tension that spurs them to rush to Bangalore after a call about Sanjana's Mother and her accident.
In Bangalore, Sanjana begins having visions of the dead conjoined twin’s soul following her, a phenomenon her husband refuses to acknowledge as real. He sends her to his former professor for spiritual healing, hoping to restore peace of mind.
During the treatment, she reveals that her conjoined twin sister Anjana always resented Kabir’s growing closeness to Sanjana. It was when Kabir told Sanjana he was coming back from abroad that she decided to separate from Anjana. It was during this operation that Anjana died, and Sanjana carries the burden of guilt for what happened. The professor tries to reassure her, suggesting that the visions of Anjana are born from remorse and subconscious fear rather than actual haunting.
At her mother’s place that night, an unseen force drags Sanjana into the outhouse, and Kabir wakes to find her unconscious there. When Sanjana awakens, she is possessed by Anjana’s restless spirit. After this possession, the line between Sanjana and Anjana blurs, and the two identities seem to share a single body with an intensified craving for Kabir. The professor, sensing something wrong, urges Kabir to keep a close watch.
The caretaker proposes that a ritual be performed on Sanjana/Anjana. After the kanjar, Anjana’s grip tightens, revealing a darker side and prompting the arrival of an exorcist.
During the ritual, Anjana finally admits that she was murdered. As she leaves Sanjana’s body, she asks Kabir to uncover the truth behind her death. When Sanjana regains control, Kabir warns that he might leave her if things don’t change. Sanjana confesses that years earlier, when Kabir called to say he was coming home, Anjana had already lost her mind and tried to kill her because she too loved Kabir. In self-defense, Sanjana struck Anjana with a glass music box, killing her, and their mother concealed the truth to protect her daughter. After seeking guidance from the professor, they vow to burn the last possession of Anjana to free her spirit.
Sanjana, Kabir, the caretaker, and her daughter-in-law follow a haunting melody to the outhouse. They uncover Anjana’s corpse beneath the floor. The caretaker and her daughter-in-law descend to fetch kerosene to burn the body, only to fall victim to Anjana’s vengeful soul. The professor arrives with kerosene but is possessed by Anjana and turns on Sanjana. As Kabir battles the possessed professor, he finds a locket he once gave to Sanjana on Anjana’s corpse. Confronting Sanjana, he learns that she is actually Anjana in disguise. She confesses that she killed Sanjana with the music box and swapped places to win Kabir’s love. Enraged, Kabir considers leaving her, but Sanjana—now revealed to be Anjana—strikes him with a chair, knocking him down. Anjana lunges with scissors, but Sanjana’s soul intervenes, and the roof collapses onto Anjana, killing her as the professor saves Kabir. Kabir gazes on as Sanjana’s soul smiles briefly and then vanishes in the flames.
