Plot

A police officer is on a chase to hunt down a dreaded gangster to fulfill his own secret agenda.

Aaditya Arunachalam (Rajinikanth), the Commissioner of Mumbai Police, is seen killing numerous gangsters across Mumbai in police encounters. He is shown to be reckless and has become the target for widespread criticism and condemnation. His action finally prompts the National Human Rights Commission of India to take action against him.

In a flashback, Aaditya, a distinguished cop, is assigned to take charge as the Commissioner of Police for Mumbai, in a bid by the police department to curb rampant drug-trafficking and prostitution in the city. He arrives in Mumbai with his daughter Valli (Nivetha Thomas), to take charge as the new Commissioner of Police. Upon arrival, he rescues three women, one of whom is the daughter of the Deputy Chief Minister of Maharashtra. Almost immediately, he initiates a major campaign to clean up drugs and prostitution in Mumbai, Pune, Nashik and Goa, using the situation of the minister's kidnapped daughter as a catalyst. During the mission, he apprehends Ajay Malhotra (Prateik Babbar), who is responsible for abducting and abusing minors under the influence of drugs. Ajay is the son of Vinod Malhotra, an influential and powerful industrialist, who becomes enraged at his son's arrest.

Later, under Aaditya's directive, the police go to the prison where Ajay is incarcerated, in order to take video evidence of him in jail. However, when the video is shown to Aaditya, a proxy is seen to be acting in place. Aaditya requests the Government of India to investigate, which is denied. Aaditya investigates and figures out Ajay escaped the country under a fake passport. Through a discreet investigation, Aaditya learns that Ajay is hiding in Thailand. He has the Royal Thai Police arrest Ajay on the charges of illegally entering Thailand with a fake passport and begins the formal diplomatic process to have him repatriated.

However, corrupt government officials and politicians under Vinod's payroll declare that Ajay is still incarcerated in India, forcing Aaditya to return to India empty-handed. Undeterred, he shoots Ajay's proxy dead under the pretext of self-defense and declares that "Ajay's" body will be revealed to the public. Forced with no other option, and to avoid public shame, the corrupt officials have Ajay secretly flown back to India and promptly executed, much to Vinod's helplessness. At Ajay's funeral, Vinod reveals to an associate that Ajay is not his son, but that of Hariharan 'Hari' Chopra (Suniel Shetty), a notorious mafia boss and international drug lord, infamously known for murdering several policemen in a brutal massacre 27 years ago.

Hari is informed of his son's death and swears revenge. He enters India via the India-Bangladesh border and silently traces Ajay's murder to Aaditya. Seeking retribution, he plots to kill them. Vinod, anticipating what would happen, tries to warn Aaditya through Valli, but is unable to do so as Valli fails to give the message to Aaditya. Vinod is later murdered by Hari for failing to protect Ajay. He attacks Aaditya and Valli by orchestrating a gruesome car accident. Aaditya is critically injured but Valli seemingly escapes with minor injuries. However, upon arriving at a hospital, doctors reveal to Valli that although Aaditya will recover, she will die, due to severe internal bleeding sustained as a consequence of the accident. Heartbroken, Valli makes a video recording of herself to her father, bidding a tearful farewell. She dies before Aaditya regains consciousness. Grief-stricken and enraged, Aaditya barges into Vinod's residence, with the intent of seeking revenge, only to learn about his death. Almost driven to the point of insanity, he turns extremely violent and begins a rampage of murdering gangsters, which brings the film back to the present.

Hari organizes an ambush to kill Aaditya and his team. He escapes, but several of his subordinates are injured. He is suspended from the police force as a consequence but is given a second chance. Perplexed about the connection between the murders of Ajay, Vinod and Valli, he discovers the video clip that Valli had recorded for him, prior to her death, which reveals a third person with a strong connection to the case. With the assistance of police records, Aaditya traces the case back to Hari. He also learns about the true link between Hari, Ajay and Vinod - Hari had handed over Ajay to Vinod to keep him safe, before fleeing India. Aaditya launches a manhunt for Hari. In response Hari gives out a bounty on Mumbai police which leads to the murder of several policemen. Now police force is afraid to step out to do their job. Aaditya vows to capture Hari in 24 hours. With the assistance from a prison's inmates (he reckons criminals know other criminals better than the police), Aaditya traces Vinod's location to the old office complex of 'Mumbai Media', owned by business magnate, Pramod Gupta, one of Hari's associates, with whom he was once cellmates in prison.

With the help of numerous policemen, Aaditya launches a raid on the complex, managing to capture Gupta and murdering all of Hari's goons, but fails to capture Hari himself. Hari retreats to the police station where he had orchestrated his brutal massacre and takes several people hostage. Aaditya arrives at the police station and engages in a bone-chilling fight with Hari, in which the former emerges victorious. He manages to incapacitate Hari and stabs him to death, thus avenging Valli's death and instilling peace in Mumbai.