Swetha, a student at SJ Arts and Science College, vanishes after being found murdered in her car on a highway, and she has not reached out since. She belongs to a circle of friends from college—Jeeva, the college magazine editor; Anjali, who is in a relationship with Jeeva; Bharath, the prankster; Vinod, the one who loves mischief; Meera, who struggles with drug use; Sharmi, Anjali’s roommate and operator at the college radio; and Maya, the radio host who has a crush on Jeeva. The campus has long circulated stories about a serial killer myth named Naga, though many dismiss it as a hoax. Yet Professor Pannerelvam remains convinced the legend is real. Behind the college sits an old laboratory, the site of a fire in 1987 that killed everyone inside. Since that disaster, the place has earned a reputation as Naga’s private residence, a chilling rumor that only grows when Maya and Anjali, after making a bet, sneak into the abandoned complex and run into Vinod, who is up to his usual pranks.
From there, the tale unfolds with a blend of superstition and skepticism. Professor Pannerabreprints a tale of Nagammal (Naga) and a British soldier who fell in love, only for her brother to bury her alive; a temple was later built over the burial site, and the college later rose where the temple once stood. The myth of a murderous force around campus persists, and Vinod’s misdirection returns to haunt the students as Anjali wrestles with the fear that something real is happening. Anjali’s suspicions intensify when Swetha’s death is officially deemed an accident—Swetha was an excellent driver, which makes the claim hard to swallow. Inspector Syed begins to suspect that a rival in Swetha’s father’s business might be involved.
Tensions escalate when Vinod tries to press Anjali in the woods near the college so he can pursue his own advances, only to meet a violent end by hanging. The killer appears to be Naga, and Anjali flees to the hostel, summoning help from her friends in confusion and fear. To complicate matters, no one believes Anjali’s account—Vinod was known for practical jokes, after all. As doubt spreads, Professor Panner and Jeeva grow suspicious of each other, adding to the growing cloud of mistrust.
Meera becomes the next victim, attacked in her dorm room with her mouth muffled, and Anjali discovers Meera dead when she investigates the sounds of her roommate’s distress. The investigation tightens its grip as Maya and Sharmi join Anjali in pursuing the truth. They uncover a magazine from Jeeva’s desk that mentions the old laboratory fire, and their search leads them to a hidden room behind a shelf where a mask with snake embroidery, a black cloak, and an axe loom as eerie symbols. The sight triggers a realization: the killer’s vestments resemble the Naga mythology, and Anjali is forced to confront the possibility that Professor Panner could be involved.
The tension spirals further when Vinod’s mother arrives at the college in a display of grief and anger, pressing for answers about her son’s fate. In response, Jeeva writes a harsh piece in the college magazine accusing Panner, which leads to Jeeva’s suspension for a week. A troubling revelation about Anjali surfaces—she carries a police record from her school days—and Jeeva presses for the truth, sparking a heated confrontation with Professor Panner in a bar where they blame one another.
Maya, meanwhile, confides in her friends that the murders—though presented as supernatural—line up with the illustrations in the old book and that Anjali’s stories have a basis in fact. The group concludes that the next murder could occur anywhere in the college. A tense moment occurs when Anjali spots a figure near the pool who looks like Naga, but it turns out to be a garbage worker. Maya and Anjali also uncover a school-day incident that may tie the deaths together: during their final year, carnival festivities on Whistle Day led to a chilling act of ragging against a junior student named Saravathy, an act that resulted in Saravathy’s suicide after she was humiliated by the group.
The pattern of disappearances continues as Bharath vanishes during the annual day, followed by Professor Panner’s murder. Maya and Anjali discover Panner’s body at Jeeva’s home, and when Jeeva arrives, Anjali escapes to inform Inspector Syed, while Jeeva and Panner vanish from the scene. Suspicion heavy-laden, Maya and Anjali come to believe Jeeva is the killer, and they confront him through the night as Sharmi sleeps in the dorm. Before they can warn Sharmi, Naga strikes again, killing Sharmi. Anjali returns to the burnt laboratory and finds Vinod, Panner, and Bharath dead, while Maya lies tied to a bed, only to awaken and trap Anjali instead.
A pivotal confrontation ensues between Jeeva and Syed, and the truth comes to light: there are two Nagas—Maya and Baji—who have been orchestrating the murders. Maya reveals that Saravathy was her younger sister, and that their parents died after learning of Saravathy’s death. Baji, their house servant, raised and supported Saravathy from childhood, and the two of them joined the college to seek revenge, with Panner killed because he uncovered the truth. As Anjali fights for her life, Baji and Maya attempt to bury her alive just as Nagamma would have, but Jeeva arrives to rescue her. Baji is killed in the ensuing struggle, and Syed shoots Maya to end the immediate threat.
In a closing coda, years pass and a new cohort of college students returns to study the legend of Naga. While some dismiss the myth, Maya appears again at the site, signaling that the tale persists. She hints that belief in Naga continues to fuel fear and, perhaps, violence, suggesting that the legend’s lure endures for a new generation that may someday face the same chilling fate.
