Idiot

The royal family is betrayed by two trusted subordinates, Sethupathi and Senathipathi, who trap them in a ventless abditory. The sole infant survives, but Sethupathi plans to kill him while Senathipathi persuades him to spare.

Many decades pass and Sethupathi's descendant Chinnarasu grows up in a village under Raasu Gounder, the incompetent head of the panchayat. He is despised by his father after disobeying in a kabaddi game, and when he is thrown out, Raasu Gounder spitefully gives him the deeds to the royal palace that Sethupathi killed.

While traveling to the palace to claim his inheritance, Chinnarasu has an accident that leaves him with delusional amnesia. He later becomes Paandi and is admitted to a psychiatric facility, beginning a new life under a different name.

Chinnarasu, now known as Paandi, is admitted to the psychiatric hospital named after Senathipathi. Sumitha, the granddaughter of Senathipathi, works there as a psychiatrist and encounters him as a patient. He befriends fellow patient Burfi and gradually falls for Sumitha, who sees him as harmless though deluded.

Sumitha receives a ring from her father that once belonged to the grandfather. The mother wears the ring while Sumitha sleeps, and she is then strangled by ghosts that haunt the family until the ring slips off. The ring's mystery triggers a strange chain of thefts and confrontations within the hospital.

The jewellery passes through many hands, from Sumitha's bag to an attendant, then to a nurse, and finally to a mysterious female patient named Neelakandi. Paandi retrieves the ring, believing it to be an engagement ring for him, but the nurse confiscates it again and it ends up with Neelakandi. Neelakandi reveals that she will help the ghosts' revenge in exchange for sacrificing Sumitha during the eclipse to resurrect her dead lover.

Thiru Don Sekar and his gang decide to kidnap Sumitha to demand a ransom from her father, setting the stage for a dramatic night. The plan unfolds under the looming threat of the upcoming eclipse, intertwining supernatural elements with human schemes.

On the eclipse night Paandi and Burfi hide in Sumitha's car to help her escape, but the gang abducts Sumitha and tries to collect ransom from Paandi and Burfi instead. The ransom is abandoned at the drop site, while Sumitha remains in danger.

Neelakandi's ghost army abduct Sumitha and take her to the royal palace, leaving the kidnappers to suspect other human invaders. The night grows chaotic as the living and the dead converge inside the palace.

The paths of the dead royal family, Paandi, Burfi, and the kidnap gang converge at the palace, while Raasu Gounder and Parimalam arrive to confront their son. Loyalties shift as living and dead vie for Sumitha's fate.

Sumitha's father enlists a priest who prepares a ritual to shield her during the eclipse, hoping to beat back the supernatural threat. Burfi interrupts the ritual, mistaking it for Paandi's wedding, further complicating the night's plan.

The priest empowers Paandi to confront Neelakandi's powers and tricks Neelakandi into believing Paandi is the reincarnation of her dead lover. When Neelakandi embraces him, the priest releases the lover's soul, enraging the ghost and causing her downfall.

With the eclipse ending, the priest revives Sumitha and rescues her from the peril of the haunted palace. The revelation of true loyalties brings a measure of peace to the surviving family as order is restored.