Nandini is on trial for Guna's murder, defended by respected lawyer Chellappa, a father figure to Sakkarai. Chellappa invites Sakkarai to the Ashtakaali festival but is soon found dead in a locked cottage with a missing gun. Sakkarai becomes the investigating officer, creating tension with Inspector Moorthy. In the locked room murder, Sakkarai finds a hidden shocker!
Amidst the festival chaos, Sakkarai grapples with the mute woman from the crime scene, desperate to uncover her identity. Nandini befriends a powerful inmate, while Malathy voices her mistrust of Inspector Moorthy. As Amman processions flood Kaalipattinam, young women from all walks of life emerge with fierce determination. Sakkarai receives a shocking call that blows the case wide open.
A verbatim confession from the 7 young women who surrendered at different police stations, each claiming to have killed Chellappa sends Sakkarai's head spinning. He requests Nandini to be his eyes and ears in the sub-jail the women are lodged in. In lieu of the festival, a low-key funeral is held for the grand man, Chellappa. Dhamu steps up in a time of need, making an immense personal sacrifice.
Sakkarai diligently searches for connections among the eight women, and Nandini offers him a promising lead. Sakkarai uncovers Chellappa's fraught relationship with the local private school, revealing a potential motive for its owner, Prayamvata. Just when he thinks he has a handle on the case, Sakkarai receives devastating new information-Chellappa may not be the savior he once believed him to be
A stage play in the festival reinstates Sakkarai's resolve to find the young women justice. Sakkarai finds a pathbreaking lead at the crime site. With fresh forensic reports, he imagines the sequence of events on the fateful night. Dhamu's shocking confession solidifies Sakkarai's new image of Chellappa. The young women in the prison pull a risky stunt. Nandini and Sakkarai get the women to talk.
10 years ago: Ravi and Naagamma are a happy, loving couple from the fishing community. Naagamma's world turns topsy-turvy when she discovers Ravi's dark secrets. She takes an extreme measure to set things right. Risking her life, she takes up the role of a protector. Chellappa gets sucked into the vortex in an effort to help Naagamma's efforts to restore a broken path.
Sakkarai learns that Chellappa has been trying to crack and nab the kingpin of the human trafficking ring for the past 10 years. Shared grief brings Sundar and Dhamu closer. A shocking development sends Sakkarai on a time sensitive chase. The 8 women finally reveal their story from the night of the murder. The elusive demon prepares for battle, putting the 8 women in grave danger.
Sakkarai fixates on the case and nails Chellappa's killer. With the identity of their demon revealed, the 8 women gear up for revenge, but their demon puts up a formidable fight. Sakkarai goes on an epic chase to save the newly trafficked kids. Just as the festival goers wash away their past, Sakkarai, Nandhini and the 8 women are presented an opportunity to let go of their past and start anew