Taut and thrilling, this fast-paced crime drama traces the twists and turns in the life of Sathyadev (Ajith Kumar), a brave and honest police officer.
Thenmozhi (Anushka Shetty) arrives in Boston to meet her niece. While leaving for Chennai, in the airport, she gets a free upgrade and sits next to Sathyadev. During the flight, she starts vomiting due to overeating and with Sathyadev's help she feels better, so she devolops a crush on him. The next day in Chennai, Sathyadev and Thenmozhi are at a cafe, when a criminal named Victor (Arun Vijay) comes to abduct Thenmozhi, but fails due to Sathyadev subduing him.
Then the film goes back to Chennai 1989 (then known as Madras) where Sathyadev's father (Nassar) is killed by a criminal. From there Sathyadev makes a decision and a few years later he is seen in a jail with Victor. With both of their help they escape from jail, get Victor married to Elizabeth alias Lisa (Parvathy Nair), and meet Matthew (Stunt Silva), a criminal. There Sathyadev infiltrates the gang as an IPS officer, kills Matthew and injures Victor. Then in an attempt to stop a gangster he meets Hemanika (Trisha Krishnan) who needs to get to a hospital due to her being pregnant. Two years later, he meets Hemanika and her child Isha (Baby Anikha). After seeing each other for four years they decide to get married with Isha's approval. On the day of their marriage, Hemanika is killed; both Sathyadev and Isha are heartbroken. Years later Sathyadev decides to quit and travels with Isha around India along with his colleague Richard's (Vivek) help. After he returns, his neighbour's children have gone missing and he discovers Victor is now helping his boss, Muruganandham (Suman), stealing organs illegally with foreign doctors to help him. Sathyadev is able to find both the children, and is also able to find their next target, Thenmozhi. Then it goes back to the present where Sathyadev keeps Thenmozhi in their house with Isha.
In an attempt to get Thenmozhi, Victor and his team kidnap Isha and is held captive along with Lisa who is also helping out. Victor said he will give Isha if they give Thenmozhi, which Sathyadev accepts. Then when they arrive at the location, they find Muruganandham and kill him. Then he finds where Thenmozhi is and saves her and Isha despite killing Lisa.
A few days later, Victor sneaks into Sathyadev's house and reveals himself as Hemanika's killer. The duo engage in a fight which ends with Sathyadev victorious; he drags a wounded Victor outside and leaves his colleagues to kill him.
Atlast Isha and Thenmozhi plan out Isha's birthday. Thenmozhi promises to be there throughout the day. Before Sathyadev takes Isha home, he reminds Thenmozhi of the pending coffee that Thenmozhi wanted to have with Sathyadev, indicating that he is ready to move on life with Thenmozhi.