The series traces the lives of shape-shifting serpents. During all seasons, the shape-shifting serpents combat evil and protect the Naagmani, the ultimate source of power, from falling into the wrong hands. So, Naagin is an Indian supernatural, fantasy, thriller, and drama television series.

Shivanya and her cousin Shesha are ichchadhari naagins who want to avenge Shivanya’s parents’ death. Shivanya identified three out of the five murderers: Ankush, Viren, and Shailesh. They killed Shivanya’s parents in a failed attempt to obtain a precious gem with magical powers called Naagmani.

Shivanya successfully gives birth to a healthy baby girl named Shivangi, despite being born six months early, three months after the first season’s events.

A widowed Shivanya does not want Shivangi to become a naagin to protect Naagmani. A saint tells Shivanya that this can be avoided by marrying Shivangi before she turns 25. Rocky, Ruchika’s fiancé and Yamini’s adopted nephew, falls in love with Shivangi. Unaware of Rocky’s relation to Yamini, Shivanya arranges for him to marry Shivangi.

Shivangi attempts to commit suicide, but she survives and becomes a naagin; she vows to protect naagmani and avenge her mother.

Shivangi is dying with none of her questions answered. However, she vows to return for revenge. Ruhi, a naagin who can shape-shift after a hundred years of penance, dances with her lover Vikrant in an old haveli under the moonlight to celebrate their highly anticipated union. However, business tycoon Andy Sehgal’s sons, Yuvraj and Aditya Sehgal, arrive there and misbehave with Ruhi, but an agitated Aditya shoots Vikrant. Mahir arrives there but cannot know what has happened. Vikrant dies, while Ruhi vows to return to revenge for her lover’s death.

Later, it is revealed that Vikrant is alive and betraying Ruhi for Naagmani.

A naagin princess, Manyata made the tough decision to relinquish her magical powers to marry Keshav, her human soulmate. Unfortunately, this decision proved regrettable as his enemies brutally attacked and killed Keshav and his entire family. Nevertheless, Manyata could escape with her daughter despite the devastating turn of events. Twenty-five years have passed since Keshav’s killing. However, the fire of vengeance is still burning in Manyata’s heart, and now her daughter, Nayantara, has become powerful again.

Recently, Naagmani is introduced in the story.

As the same goes, this series is all about love, betrayal, romance, naagin, and most important, NAAGMANI!