Varun, a military doctor working in the Indian Army Medical Corps is a strict and practical person. While returning home from an operation, he receives a voicemail from his fiancée, Padmini, who urges him to call off their upcoming wedding. While enquiring about her sudden change-of-decision with her family. Padmini belittles him for being emotionally distant and apathetic. While leaving, Varun and Padmini's family learns that Chinnu has gone missing. The family lodges a complaint with the police – which in turn appoints Bhagat, a low-ranking police officer, to monitor the family's communications.

Disillusioned with the police's sluggish progress, Varun plots to kidnap the ACP's daughter, believing that the resulting investigation would be more competent. His plan works, and the police nab almost every major criminal related to child-kidnapping. Varun singles out three criminals (Kamala Kannan, Kamesh, and Prathap), noticing that they were present around Chinnu's school at the time of her disappearance. Varun sedates them, and interrogates them by blackmailing them with their kidneys; he had apparently removed. Kamala Kannan confesses to kidnapping Chinnu, and handing her over to a child-trafficking network. Varun recruits one of the kidnappers Pratap and two gangsters, Mahaali and Killi, to assist in his investigation.

Varun's search leads him to twins Alvin and Melvin, both of whom are responsible for child-trafficking and prostitution. Varun and Padmini's family confront the duo in the Chennai Metro, and succeed in separating the duo and abducting Alvin. Desperate to save Alvin, Melvin concedes to release only one girl from his group of kidnapped girls. Although Chinnu is among them, Varun demands Melvin to release all the girls, despite Padmini's objections. Melvin refuses, but hints that the girls are being taken to Goa. Varun, Pratap, Mahaali, Killi and Padmini's family follow Melvin to Goa, where they discover that the true mastermind behind the recent kidnappings is Terry, the owner of a high-end resort.

Varun orchestrates a drama, in which he has Mahaali and Killi and Padmini act as if the duo were kidnapping her and simultaneously has Padmini's family urge Terry to find her. As per his plan, Terry traces Padmini's kidnapping down to Varun, who poses as a child-trafficker masquerading as the owner of an ice-cream parlour. Varun demands Terry to give a girl to him, as compensation for saving Padmini. Unbeknownst to Terry, Varun had arranged for his friend, Colonel James Anderson and his team of commandos to apprehend Terry. Terry escorts Varun to his base of operations, located on a remote island. Varun discovers than Terry's victims are primarily underage girls. Realising that any action would endanger the kidnapped victim's and Chinnu's lives, Varun calls off the operation despite James' protests.

Determined to save the girls' lives, Varun initiates his backup plan. He negotiates a deal with Terry and Terry's father to ship a consignment of 40 girls to Don Pablo El-Fino– a fictitious Brazilian child-trafficking's boss (actually Varun's father in disguise). Concurrently, Terry organises a meeting with his associates to discuss the upcoming deal; Melvin is among those in attendance. Varun discreetly orders Melvin to kill Terry; the latter's attempt to do so is surprisingly thwarted by Varun himself (in order to gain Terry's trust). Terry interrogates Melvin, learning about Alvin's abduction and Melvin's actions were purely out of desperation. Unwilling to reveal the identity of Alvin's abductor, Melvin is killed by Terry. Later, while going through the family profiles of the twins's latest kidnaps, Terry discovers Padmini's family is among them and deduces Varun's plan.

Terry later has Varun and the family apprehended and takes them to his island, intending to kill them. However, Alvin appears, seeking revenge for Melvin's death. Alvin reveals he had abducted Terry's father and agrees to spare him, in return for letting Varun and the family along with all the other girls. After they leave, Alvin kills Terry's father to avenge Melvin's death, where Terry kills him in retribution. Elsewhere, Varun realises that he had left a girl behind and returns to the island alone. Terry apprehends Varun and plans to kill the lone girl in front of him, but is thwarted by James's team and Bhagat, who had infiltrated his base. Varun escorts the girl to safety while James's team kill Terry and his henchmen. 3 months later, Padmini reconciles with Varun and they get married in presence of their family and friends.