The Charaka Samhitha, an ancient text of miraculous cures, is kept hidden and guarded by snakes. Will Bhavani and Arjun, its protectors, succeed in keeping the book safe from the clutches of evil men?
The villagers are warned not to venture out till the day of Naga Pournami at night by the village head. Bhavani and her friends come home. She lies to her grandmother that she lost the amulet.
Sunanda and Panicker argue about opening the temple gates to the public. Arjun finds the ‘Nagaraksha’ amulet that Bhavani loses. A villager gets ready to take Bhavani to Nagapuram.
Gurudevan summons Kalakeyan. Kalakeyan sets out to know the truth behind the temple. The devotees perform ‘Mahadeva Puja’. Nagadevatha attacks Kalkeyan and his people.
When Bhavani reaches home, her father questions her. Bhavani's grandmother offers prayers to Lord Mahadeva. Malli, who regains consciousness, shares her woes with Bhavani and her family.
Bhavani introduces her friends to her grandmother, who feeds her. She sees her older brother's photo and thinks about him. Bhavani fights with her grandmother for scolding her.
The passwords to the laptops fail to work as Arjun and Bhavani’s devices get exchanged. Bhavani hides the fact that she lost the amulet from Annapoorna. Bhavani goes to the temple with Annapoorna.
Nagadevatha drinks the milk offered by Bhavani. Arjun’s mother briefs him about the amulet. Bhavani hides the fact that she lost her amulet from her family. Sanvi scolds Arjun for losing the laptop.
Bhavani gives Brahmaraj money to get a duplicate ‘Ashtanaga’ amulet made. The village head punishes Shekhar for breaking the village norm. Arjun goes to Nagapuram on the night of Pournami.
Nagadevatha stops Arjun from going to Nagapuram and seeks to know why he wants to go there. Later, Krishnanathan shelters Arjun who reaches to exchange his laptop with Bhavani’s.