Aalavandhan 2001

[Vijay Kumar], a skilled Black Cat commando, leads a high-stakes mission to rescue tourists held hostage by terrorists in Kashmir. The operation goes off without a hitch, and in its wake he reconnects with his girlfriend Tejaswini, a news presenter, as they plan to marry. Tejaswini reveals she is pregnant, sharing her HCG report with him, a moment that deepens their bond and commitment.

Meanwhile, Nandu, Vijay’s twin brother also known as Nanda Kumar, has spent years confined to a mental asylum after being accused of murdering their stepmother, Jayanthi. Nandu, a schizophrenic with paranoid delusions, has lived under careful watch, and though Vijay has always tried to care for him, the doctors warn that Nandu could pose a danger to society. When Vijay and Teju try to share the news of their wedding with him, Nandu develops a warped perception and begins to see Teju as Jayanthi herself.

Believing he must protect Vijay, Nandu escapes the asylum after killing two inmates, Sulthan and Paasha, leaving no trace of his whereabouts. He later confronts his maternal uncle, who had a hand in his confinement, and the confrontation ends with the uncle choking to death in shock. The family’s dark past begins to surface more clearly.

[Vijay] and Teju go ahead with their wedding, but the shadow of Nandu’s escape looms large. A doctor initially denies the possibility of Nandu’s flight, but postmortem evidence tied to the violence—linked to Sulthan’s case—begins to persuade him that Nandu is at large. Nandu sets out on a chilling quest to kill Teju, leaving a threatening message at Vijay’s home. He experiences vivid hallucinations of his deceased mother and descends further into violent behavior. His attention is drawn to Sharmilee, a socialite, after seeing her posters; Sharmilee is charmed by his quirky behavior when they meet by chance. However, a drug-induced moment triggers memories of Jayanthi’s abuse, and Nandu brutally murders Sharmilee. He regrets what he has done and burns her body, but leaves enough evidence behind to help Vijay identify him as the killer.

To escape Nandu, Vijay and Teju retreat to his ancestral home in Ooty, where Nandu secretly follows. There, they uncover Nandu’s diary, which sheds light on the troubled past that forged their fractured family. Their mother Priya died by suicide after learning of their father, Santhosh Kumar’s affair with Jayanthi, who became their stepmother. The painful history reveals why the twins despised Jayanthi, and it explains the tense tensions at home. A coin toss decided which twin would stay with their uncle and which would go to boarding school; Vijay went to boarding school, while Nandu remained behind. Santhosh later suffers another heart attack, and the mounting turmoil culminates in tragedy when Jayanthi’s scheme and the family’s broken trust contribute to their mother’s death.

Back in the present, Nandu tracks Vijay and Teju to Ooty. A tense pursuit unfolds, and Vijay manages to save Teju during a dangerous encounter. Nandu follows, leaving chaos in his wake as he evades capture and kills several people along the way. The final showdown erupts between the brothers: Nandu overpowers Vijay and corners Teju, who defends herself with a belt, triggering his traumatic memories of Jayanthi’s punishments. He envisions his mother pleading with him to join her as Jayanthi’s torment continues, and he finally apologizes to Vijay and Teju for his actions. In a climactic moment, Nandu ignites gas cylinders, causing a massive explosion that kills him and ends his torment.

Months pass, and Teju reveals she is carrying twins. She worries about the kind of childhood their children will have, fearing a repeat of the trauma that shaped their own lives. Vijay reassures her that their children will be raised in a loving and supportive environment, free from the shadows of their past. The film closes on a note of cautious hope, with the couple looking toward a future shaped by healing and resilience.