Yamuna, Nayanthara, a sharp journalist, escapes an arranged marriage and seeks refuge with her grandmother Parvathy Paati, Kulappulli Leela. Across town, Amudhan, Kalaiyarasan, an earnest investigator, is digging into a string of mysterious deaths that have unsettled the local community. In the midst of this tension, Yamuna teams up with Parvathy Paati, Mani, Yogi Babu, and Mani’s young nephew Babloo, Ashwanth Ashokkumar, to start making fake ghost videos for YouTube as a way to entertain and cope with fear.
Yamuna is haunted by a ghost, a presence that intensifies one night when she and her grandmother are attacked. She wakes up in a hospital to learn that Parvathy is alive but in critical condition, only to be told soon after that Parvathy has died. In the meantime, the ghost, Bhavani, appears to Amudhan and insists that revenge is not the answer—her apparent mission is to kill Yamuna. Bhavani reveals that her work is nearly complete, and Yamuna becomes the target of a chilling supernatural countdown.
At Parvathy’s funeral, Yamuna’s parents push back against Mani’s ghost-video scheme. Through her own research, Yamuna discovers that Babloo never existed as a real boy—he was a vision, a ghost from her experiences. Driven by curiosity, she tracks Bhavani and Babloo to Amudhan’s home, where a butterfly guides Yamuna out of her bedroom and she witnesses Bhavani and Babloo’s ghosts together. Frustrated with the hauntings, Yamuna chooses to engage with the spirits rather than flee, stepping back into the haunted house. She and Amudhan then consult two priests who promise to perform prayers to the god Bhairava and set the stage for a ritual: Amudhan must dig up Bhavani’s corpse in the cemetery and destroy it with a trident so Bhavani cannot use the body again. With the rite carried out, Bhavani appears, though she remains subdued under religious chants.
Bhavani’s past begins to unfold. Her patriarchal father, devastated by the birth of another girl when his wife fails to produce a boy, dies by lightning, an accident that the village interprets as a sign of a curse on Bhavani. Her mother and sister grow to resent her. On Bhavani’s sixteenth birthday, her elder sister gives birth to a stillborn baby, reinforcing the awful rumor mill that surrounds her. Bhavani endures abuse and humiliation, and she crosses paths with Amudhan at school, where he falls in love with her. When Amudhan’s father discovers their relationship, he sends Amudhan to study in New Delhi. Bhavani faces rejection from many suitors because of her dark complexion, and a brutal night arrives when her brother-in-law attempts to assault her. Her family ultimately expels her, widening the gap between her and the world she hopes to join.
Bhavani’s journey brings her to Chennai, where she does odd jobs at a hotel and eventually reconnects with Amudhan at a restaurant. He proposes, and she accepts. On the day of their wedding, Bhavani refuses the advances of a beer-company room owner who asks her to sleep with him. She hurries to the elevator where Yamuna happens to be, but Yamuna’s refusal to let Bhavani in makes Bhavani late to the marriage office. En route, she faces harassment from two men and is briefly jailed when a police officer arrests her; the real culprits are later cleared. She also meets Babloo again, and together they try to cross the street, only to be struck down by a drunken lorry driver.
Bhavani reveals that she killed everyone who had disturbed her life. Yamuna imagines how Bhavani’s life could have turned out if she had stepped into the elevator that day. When Yamuna asks Bhavani what she wants, the ghost answers that she desires Yamuna’s body so she can live with Amudhan. Yamuna agrees, accepting the sacrifice to pay for her own mistakes. On the wedding day between Bhavani and Amudhan, Bhavani possesses Yamuna and sits in for the ceremony, but Amudhan refuses to share Yamuna’s body with Bhavani. He ultimately takes his own life, telling Bhavani that they can now be together in the afterlife. A prophetic vision then shows Bhavani and Amudhan wed at the sub-registrar’s office.
The film closes at the cemetery, with Yamuna present at the graves of Bhavani and Amudhan as the same red butterfly from Yamuna’s visions flits by, signaling a chilling, unresolved fate and the enduring pull of vengeance, memory, and the supernatural.
