Iraivan

ACP Arjun is known for an unorthodox, lethal approach to neutralizing suspects. He also harbors affection for Priya, the sister of his friend Andrew. He hesitates to marry because his enemies from years of aggressive policing could retaliate.

Arjun and Andrew are assigned to the brutal case of a psychopathic killer nicknamed the Smile-Killer, who leaves distinctive smiley notes and abducts young girls. The city sharpens with fear as the murders continue.

Andrew confronts the killer and is killed in the line of duty, leaving Arjun devastated. This tragedy intensifies Arjun's resolve and distrust of the system he serves.

Haunted by the trauma, Arjun resigns from the police and withdraws from fieldwork. He and Priya launch a cafe, seeking a peaceful life away from crime.

About a year passes and Brahma reportedly escapes from prison. Dr. Shanmugam, Brahma's caretaker, is found dead, and Swetha—his daughter—becomes the killer's next marked victim.

Arjun receives a death threat letter that appears to come from Brahma. The Smile-Killer's rampage grows more brutal, and he starts sending video footage of the victims to families and the media, fueling public fear.

Shalu, the sole survivor of a previous encounter with Brahma, disappears again, prompting renewed police focus on the case. There is a belief that Brahma abducted her to complete his unfinished task.

Arjun locates the captivity site where Shalu is held—the same place Brahma was captured before. He confronts Brahma and learns that someone else has been using Brahma's name for the latest murders, though Brahma refuses to reveal the others.

Police arrive and fatally shoot Brahma. The investigation continues as signs point to a copycat operating under Brahma's name.

Arjun suspects Babu, an assistant to Church Father Sebastian, as the copycat after signs point to him. However, evidence later implicates Arjun when the video of Shalu's captivity appears to be sent from his own location.

During the attempt to arrest Babu, Arjun uses his typical aggressive methods. The police intervene to save Babu, and Arjun confesses to kidnapping Shalu and sending the video to a TV channel to trap Brahma.

Public sentiment shifts as Babu goes to the media about his mistreatment by Arjun and the police. Meanwhile, Arjun uncovers more evidence at Babu's store linking him to the crimes.

Jasmine, Andrew's widow, reveals that Babu has abducted her daughter Sophie and will share Sophie's location only if Arjun cooperates. Arjun agrees and prepares to meet Babu.

A staged hostage exchange leads to Priya joining the scene. Arjun intervenes, incapacitates Babu, and saves both Priya and Sophie.

The police fake Babu's death and keep him in secret custody to avoid public backlash. The film ends with Arjun and Priya contemplating how to deal with Babu in private.