Soon-to-be-released convicts Raja and Babu cross paths with Manohar, who sits on death row. He reveals that his sister Sumathi was kidnapped by a taxi driver and taken to the notorious playboy Muthuraaj, who raped and killed her. Muthuraaj murdered the taxi driver and framed Manohar with his elder brother Rajamanickam, along with his ally Jayaram and a corrupt police inspector Nallasivam. Raja and Babu believe Manohar; Raja stalls his execution by fracturing his left arm. Once released, the two men initiate an elaborate plan.
Under the cover of a fake income tax raid, [Raja] and [Babu] search [Nallasivam]’s house and uncover a trove of illegally earned wealth, forcing his wife Kalyani to sign a paper confirming the wrongdoing. Nallasivam learns of the “raid” and threatens to arrest the pair, but they gain leverage by duplicating the signed document and spreading copies. The ruse sets the stage for a deeper, long game.
Raja soon falls for Geetha, a police inspector. He orders [Babu] to try to win over [Rajamanickam]’s daughter Chithra as part of the plan, but the scheme backfires when Geetha’s loyalties come into play. Raja discovers Geetha is Nallasivam’s daughter and fabricates a cover story about being a CBI officer. He uses this lie to blackmail Nallasivam into helping him infiltrate Muthuraaj’s service as a new bodyguard. [Babu] later genuinely falls for [Chithra], who returns the feeling. Although Raja soon reveals his true identity to Geetha, she accepts him despite the corrupt roots of her father.
Pressed by Raja, Nallasivam introduces [Babu] to [Rajamanickam] as a millionaire in love with Chithra; [Rajamanickam] arranges their marriage. During the ceremony, Babu declares that he knows the group’s crimes and will marry Chithra only if they confess in writing. When [Rajamanickam] refuses, Babu reveals his true identity and cancels the match, telling Chithra that her father refused to grant the dowry he asked for. [Rajamanickam], [Jayaram] and [Muthuraaj] realize that Nallasivam lied to them, and that Babu is aiding Manohar’s cause.
For more than two decades, [Rajamanickam] has hunted for a secret known only to [Kandhasamy], Manohar’s father, who is held captive in a basement. Kandhasamy’s amnesia is jolted with a rope, and the truth begins to surface, but he refuses to disclose it. Rajamanickam imprisons Kandhasamy and his family to force the truth, only for Kandhasamy to resist. In a shocking turn, [Rajamanickam] murders IG [Sriram] and his wife while disguising himself as Kandhasamy, sparing their son [Babu] so that the blame would fall on him. The family is later rescued by Raja and Babu, and Padma reveals their broader captivity. On learning the truth, Raja and Babu reunite and vow vengeance.
Geetha and Chithra join Raja and Babu in their plan to avenge the past. Chithra leads Rajamanickam to a meeting with Raja and Babu, and at Jayaram’s prompting he agrees to sign a paper incriminating Muthuraaj in exchange for the cave’s location—the “dowry” that would secure Chithra and Babu’s marriage. Chithra records Rajamanickam and Jayaram’s conversation on tape and hands it to Muthuraaj, who plots revenge together with Nallasivam.
Kandhasamy, Rajamanickam, Jayaram, Babu and Raja finally reach the cave and uncover a cache of gold bars. Rajamanickam signs the incriminating paper as promised, but Raja and Babu intend to see him arrested for his crimes. Muthuraaj and Nallasivam arrive with a reckless onslaught of thugs and bombs; Rajamanickam and Jayaram are killed, while Raja, Babu and Kandhasamy escape. Muthuraaj and Nallasivam drive off with the treasure, only to be stopped by Geetha. Manohar, now fully healed, is exonerated and peace returns to those who fought for the truth.
