The Chennai city lives in fear of a psycho killer. Confidence in the police wanes until Arjun and Andrew join. Arjun, with a dark past, unveils truths about the killer. They finally arrest the killer but he escapes and chaos ensues. Arjun loses Andrew and his love, descending into darkness. The story follows Arjun's journey to vanquish the killers.
When Arun (Udhayanidhi Stalin) comes across an innocent woman in an unstable condition struggling to drive her car back home, he reaches out for help, only to find her dead body, the next morning in the car. What happened to the lady? Who killed her? What's the mystery lying beneath?