To average his father's death at the hands of Takshaka, the king of serpents, Janmejaya held a snake sacrifice. Mantras were chanted to destroy the snakes but Takshaka did not appear. The head priests thought that Takshaka had sought protection from Indra. They chanted a special mantra to compel Takshaka had sought protection  from Indra. They chanted a special mantra to compel Takshaka to appear and fall in the sacrificial fire along with Indra. Soon, both Takshaka and Indra appeared and fell into the fire together. When Indra saw that Takshaka was bound to die, he deserted him.

Meanwhile, Jararkaru, Takshaka's younger sister, ordered her son, Astika, to save Takshaka. Astika approached Janmejaya and requested him for a boon. He said that the snake sacrifice had led to the death of millions of snakes and if Janmejaya spared the remaining few, including Takshaka, he will be glorified. Sage Vyasa advised Janmejaya to grant Astika's request and end the snake sacrifice. He agreed and thus, Takshaka was saved.