Inspector Bejoy, [Narain], commands a tense citywide operation after a van carrying 900 kilograms of cocaine valued at over ₹800 crores is intercepted. The narcotics and the suspects are held at the commissioner's office, a move that threatens Adaikalam, a notorious drug lord based in Trichy whose identity remains hidden from authorities. In retaliation, his brother Anbu plots to retrieve the seized drugs and eliminate the officers who foiled him.
During a retirement party for the Inspector General, Rohypnol is mixed with alcohol to drug the senior officers, leaving them unconscious. Bejoy, who is on medication and thus unaffected, tries to move them to a hospital to prevent panic. He recruits Dilli, a recently released prisoner, who longs to be with his daughter Amudha, Monekha Siva at an orphanage, to help secure the officers. Kamatchi, a caterer at the party, lends a hand, and together they use his truck to transport the incapacitated officers. Anbu's gang closes in, led by his lieutenant Tips, while Adaikalam’s interests loom in the background.
At the commissioner's office, Bejoy has Constable Napoleon, [George Mariyan], and a group of college students detained for drunk driving secure the building and block Anbu’s men from freeing detainees. Dilli defends the group against a mounting assault, holding the line until reinforcements arrive.
Bejoy discovers that Adaikalam himself is among the captured smugglers. He briefly considers a prisoner exchange with Napoleon and Anbu, but cancels it after this revelation. Anbu infiltrates the office, but the students subdue him.
As Dilli, Kamatchi, and Bejoy approach with the unconscious officers, Anbu's heavily armed gang ambushes them. Paalpandi, a corrupt officer pretending to have recovered, stabs Dilli, and Bejoy is overpowered. Ajhas Ahmed, Bejoy’s informant, Kanna Ravi is killed by Tips. Dilli recovers and defeats the attackers, rescuing Bejoy and Kamatchi, and killing Paalpandi.
Back at the commissioner's office, Anbu orders the execution of one of the students, prompting Napoleon to subdue him with a fire extinguisher. Adaikalam, witnessing this, vows revenge. Dilli enters via a hidden passage and helps the students escape. He and Napoleon set out to destroy the narcotics, discovering a confiscated M134 minigun and using it to wipe out Anbu’s forces. A doctor revives the unconscious officers, and Stephen Raj, Hareesh Peradi, the Zonal Head of Narcotics Division, is arrested for his involvement.
Bejoy thanks Dilli and promises him a better life. Dilli is reunited with Amudha, Monekha Siva, brought by his probation officer, Nalini, Malavika Avinash. In the final scene, Dilli, Amudha, and Kamatchi walk toward a fresh start, while Adaikalam, from his prison cell, implies that he knows Dilli personally.
