Nadu Iravil

Dhayanandam, a wealthy old man living alone with his wife Ponni, learns from his doctor that his cancer has spread beyond cure and he has only a few days left to live. He makes arrangements for his siblings to visit and stay with him during his remaining days, despite harboring resentment towards them for past treatment. His decision includes keeping his condition and imminent death a secret from his family.

Dhayanandam's siblings arrive on the island, hoping to gather his wealth after his death. Tensions rise as old family grievances resurface, and the atmosphere becomes tense with suspicion. Dhayanandam's aggravation towards his siblings is evident, especially regarding his marriage to Ponni, whom they disdain.

Over the course of the next few days, family members are murdered one after another. The remaining guests become suspicious of each other and consider Ponni, Dhayanandam, and Dr. Saravanan as potential suspects. The island's isolation intensifies the feeling of dread among everyone present.

As murders continue, the guests accuse Ponni, Dhayanandam, and Saravanan of being responsible. With no means to contact the outside world, they are trapped on the island and demand to leave, but Dhayanandam insists they cannot do so without his permission until the killer is caught.

Dhayanandam allows Jambu, his injured brother, to leave the island, but Jambu refuses to go. Jambu's son Ragini becomes close to Dhayanandam and Ponni. That night, Ragini witnesses what appears to be Dr. Saravanan pushing her father Jambu down the stairs with his wheelchair, raising suspicion among the survivors.

Later that night, Ponni is pushed from the rooftop and killed amidst the chaos. Dhayanandam, devastated by the loss, declares he will leave his wealth to Ragini, showing his emotional attachment and grief over the tragedy.

While Ragini plays the piano to calm Dhayanandam, a masked killer dressed as Dr. Saravanan attempts to stab her. Dhayanandam manages to shoot the attacker, who collapses revealing himself just as the doctor appears at the top of the stairs, shocking everyone.

Ragini unmasks the killer as Jambu, Dhayanandam's youngest brother. Before dying, Jambu confesses he was not crippled or blind and that Ragini was not his daughter but his nurse. He reveals he committed the murders to inherit Dhayanandam's wealth alone.

In his final moments, Dhayanandam agrees to distribute his wealth among his siblings and servants, fulfilling his last wishes. He then succumbs to his illness, bringing the tragic and suspenseful story to a close, with justice served but somber farewells exchanged.