Nadigan

Vishwanathan poisons Raghu to keep all profits for himself, then makes the death look like a suicide. He attends his daughter's wedding later, publicly feigning grief to protect his image. This act of murder triggers a chain of events that drags the story toward a dangerous revelation.

A secretly recorded conversation captures Vishwanathan discussing the murder with a henchman. The videographer hides the incriminating video cassette in Geetha's bag just as she flees by car. The hidden footage becomes a dangerous thread that ties Geetha to the crime.

Vishwanathan's men confront and kill the videographer inside a theater, attempting to erase the evidence. The body disappears afterward, leaving the crime unresolved for now. The missing footage keeps the danger alive for Geetha and her family.

Vishwanathan's operatives close in on Geetha, who unknowingly carries the incriminating cassette. She flees, hoping to outrun the danger and keep the evidence from falling into the wrong hands. The pursuit tightens the stakes for the ensemble.

Geetha, Radha, and their siblings live with their spinster aunt Anandha Karpagavalli at a vast Island Estate in Kodaikanal. Karpagavalli enforces old-fashioned discipline that confines the teenagers. The estate's isolation sets the stage for the ensuing drama and danger.

Raja, a street performer, meets Devaraj on a train and accidentally swaps their suitcases. He finds Devaraj's job offer letter and decides to seize the opportunity to help his mother. Desperate circumstances drive Raja to impersonate Devaraj.

Disguised with a beard and white hair, Raja takes Devaraj's place and is hired as the Island Estate's music teacher and caretaker. He quickly wins Anandha Karpagavalli's trust, who grows fond of the “unmarried elderly” man she believes is Devaraj. The deception plants him firmly inside the family.

The real Devaraj cannot locate the Island Estate due to language barriers and confusion about the location. His search underscores the widening gap between the two men and the risk of being exposed. The situation grows more tense as time passes.

Geetha and Radha attempt to outsmart the supposed Devaraj, but Raja maintains his cover and influence in the estate. Their plans backfire as the household becomes more dependent on the disguised musician. The sisters' resistance wanes as the deception deepens.

Raja intervenes when Vishwanathan's henchmen corner Geetha, rescuing her from danger. In the moment, Geetha realizes the man she has grown close to is Raja, not Devaraj, and she begins to fall for him. The revelation complicates their already tangled loyalties.

Kurangu Kannayiram hides in Raja's house while evading the police and ends up blackmailing Raja into letting him stay. The pressure creates a volatile dynamic that threatens Raja's carefully maintained disguise. The alliance with Kannayiram adds a new layer of danger to the plot.

Vishwanathan dispatches two women to Geetha's house to retrieve the incriminating cassette. The chase around the cassette raises the tension among the main characters. Geetha meanwhile pushes to align with Raja by prompting Karpagavalli to consider him as a groom.

After meeting Raja, Karpagavalli relaxes many restrictions and contemplates him as a potential groom. She invites him to stay and begins to view his influence in the household with a favorable eye, unaware of his true identity. The line between affection and deception becomes thinner.

The truth about Devaraj is revealed when Raja's disguise is uncovered, and Geetha learns he is the man she knows as Raja. The cassette resurfaces as Maya sends it to Chinni, and Vishwanathan's henchwoman abducts Geetha to retrieve it. Raja and Kannayiram lead a rescue to save Geetha's family, resulting in arrests of Vishwanathan's men; the real Devaraj eventually arrives at the Island Estate to take up the music teacher position.