While digitizing archived cases, the diligent cop Sasi uncovers a spine-chilling dacoity-murder from years past and reaches out to Theeran Thirumaran, the seasoned police officer who once led the investigation, to dissect the case and see what memory might still hold.
1995: Theeran is in police training college, tops the TNPSC exams, and returns to his hometown of Thanjavur, where he begins a life with his partner, Priya Theeran. As a brutal gang of dacoits wrecks a house along Tamil Nadu’s highway, killing everyone inside and looting their belongings, Theeran’s methodical, sometimes unorthodox approach earns him attention in the police force. His rising reputation leads to a transfer to Ponneri after a brutal dacoity attack, where he teams up with Police Inspector Sathya to pursue the case. Yet their early investigations stall, leaving the truth elusive.
2003: Theeran, Sathya the inspector, and a cadre of fellow officers roam across India in search of the gang’s fingerprints. He learns that these dacoits belong to the remaining tribal groups formed in the wake of India’s independence. The laxity of senior officers slows progress, and the case is temporarily shelved. The situation intensifies when the gang raids the house of a ruling party MLA, killing him, and shifting public pressure onto the government. In response, the Home Minister grants Theeran broad powers and commands a dedicated team to nab the culprits.
2004: The pursuit intensifies as a fingerprint match leads them to a prison in Uttar Pradesh, and the team races to a lorry station before the gang can slip away toward Ponneri. The dacoits strike Sathya’s house, killing his wife, while Sathya’s daughter is saved and [Priya Theeran] is placed in a coma. Fueled by grief, Theeran, with support from higher-ups, marshals a team to capture the gang’s leader, Oma, who operates with ruthless efficiency. They camp in Rajasthan, coordinating with a local officer, only to learn that Oma’s followers mostly stay in their village and resist capture when the team visits.
As the case unfolds, Theeran learns of Priya’s death, a blow that hardens his resolve to bring Oma to justice. The team discovers a cunning way to draw Oma out of his village, and they manage to detain the organizer and one gang member, placing them in custody. Oma swears vengeance on Theeran and his team. A crucial lead points to Oma riding a train, where the operation is to be staged, but Oma’s right-hand man, Khali, proves formidable, beating back several cops. Theeran arrives just as Oma and Khali escape after a chaotic clash that sees Oma pull a chain and flee with Khali. A local shepherd offers the team shelter for the night, and Theeran lays a careful trap to bring Oma back.
The pursuit continues as Theeran’s plan unfolds: he and his team move through the village, ambushing Oma’s intrusions with a tactical counterattack and eventually killing all of Oma’s operatives except Oma and Khali. In a desperate escape, Oma sets the settlement ablaze and makes off with Khali, but Theeran shoots Khali dead on the road. Theeran then pursues Oma through the night, finally overpowering him after a brutal confrontation and dragging Oma back to Tamil Nadu to face sentencing.
2017: It is revealed that Theeran has settled into a dull, routine post in the traffic vigilance department, living alone and following a straightforward path. Sathya and his daughter visit him, and Sasi, impressed by his long career and relentless pursuit, salutes him in quiet glory.
