An ancient palatial house, believed to be occupied by a vengeful spirit of a Courtesan named Nagavalli, is purchased by an Engineer, Ramesh, and his wife, Ganga. While exploring their new accommodation, Ganga finds out that there is a room that is under lock and key, and no one has ever dared to enter it. She locates a key and opens the door. Shortly thereafter a number of bizarre incidents occur, prompting Ramesh to enlist the assistance of his Psychiatrist friend, Dr. Vijay. Neither Ramesh nor Vijay are aware that the incidents are generated by Nagavalli, who is on an unstoppable and gruesome mission.