Kaashmora and his family are con artists who cheat people in the name of black magic and dark spirits. One day, a PhD research student named Yamini joins Kaashmora, only to gather evidence and expose him to the public. Kaashmora's fame brings him to a superstitious and fraudulent minister. Kaashmora earns the minister's trust. When the income tax department raids the minister's house, the minister asks his henchmen to transfer all of the illegal money to Kaashmora's house. Seeing this as an opportunity to escape and settle abroad, Kaashmora's family escapes with the money. Meanwhile, Chelapathy Rao seeks Kaashmora's help and brings him to a haunted bungalow in the outskirts of Tamil Nadu and Andhra Pradesh. In the bungalow, Kaashmora is haunted by actual ghosts.

Back in Chennai, the minister learns that Kaashmora is a fraudster and sends his henchmen to kill his family. The henchmen try to get Kaashmora from the bungalow but are unable to do so as the ghost beats them all and drags Kaashmora and his family inside the bungalow. Inside, they meet a broker who got trapped inside the bungalow for a long time. The broker says that the bungalow was once a princess's palace. Ever since her death, residents and owners of the bungalow had met with an ill-fate. He also tells that there are 13 ghosts in the bungalow. The trapped people meet the ghost of Raj Nayak, the head of all 12 ghosts. Raj Nayak asks Kaashmora to help him, and his subordinates reach the spiritual world. He then locks them in the castle. That night, a young girl in Kaashmora's dream leads him to a locked door within the castle.

Waking up, Kaashmora follows the same route, but is stopped by Yamini, who reveals to him that Chelapathy Rao, the man who led him here, died 75 years ago, and it was his ghost that led Kaashmora, as well as Yamini, to the bungalow. Kaashmora searches the castle and gets hold of an old book that dates back 700 years. Raj Nayak was a self-obsessed warlord and a womanizer. The king remained silent and did not interfere with Raj Nayak's growing atrocities because of his military prowess. One day, Princess Rathna Mahadevi elopes with her lover, who is the enemy kingdom's prince. The king announces that he will marry off Rathna and give away half of his kingdom to the man who finds her. Raj Nayak kills the prince and forcibly brings Rathna back. He demands to be wed to the princess and wants the other half of the kingdom as dowry. When opposed, he kills the crown prince and the king. Raj Nayak then marries Rathna and crowns himself King. However, Rathna has other plans. She and her friends seduce Raj Nayak and his subordinates. While Raj Nayak's subordinates are burned alive, Raj Nayak is beheaded by Rathna. However, he kills her before dying. Before breathing her last breath, Rathna places a curse on the 13 men, preventing them from reaching the spiritual world.

Since then, Raj Nayak and the other 12 ghosts had haunted the palace and its occupants. An exorcist once had predicted that Raj Nayak and the other ghosts would reach eternal power if they are able to sacrifice the lives of five people belonging to the same family with the same birth star (Rohini). The sacrifice should be performed by a lady who is the only woman in her generation. This should happen during the Navakaali Pournami that occurs once every millennium. Kaashmora recollects that his family members all have the same birth sign and that Yamini is the only woman in her family.

That night, Navakaali Pournami occurs, and Raj Nayak forces Kaashmora and his family to a guillotine. The young girl from Kaashmora's dream appears, and turns out to be Rathna's reincarnation. While Rathna and Raj Nayak fight each other, Kaashmora fends off the subordinate ghosts with the help of a magical sword. Rathna's conscience leads him to a chamber within the castle where Raj Nayak's remains are. Using the sword, Kaashmora destroys the remains, making Raj Nayak vulnerable. Rathna destroys Raj Nayak's spirit, and it goes to the underworld. The other spirits flee the castle to the spiritual world. Kaashmora and his family get out of the castle, and he claims that he has destroyed the spirits and cleansed the centuries-haunted bungalow. Kaashmora's family tells the politician that the money stolen from the politician has been kept by the ghost.