We have kept one important story aside for no particular reason. That has something to do with the context in which the story of Mahabharata was told.
We have heard how the lone surviving prince of the Bharata war was killed by the bite of serpent Takshaka. His son, Janamejaya, was only a child when that happened. He was installed as king of the vast Kaurava empire while he was still young. He ruled the land with the able guidance of his ministers.
It was from his ministers that he heard the story of his father’s untimely death. He developed a feeling of vengeance to all serpents, especially to Takshaka as a result. How his father would have escaped if only Takshaka did not prevent the Kasyapa Brahmin from giving the antidote to the snake’s deadly poison made the young prince even more revengeful.
Janamejaya consulted his ministers on how to avenge the killing of his father. They advised him to get able Brahmins to perform a serpent sacrifice. Such a sacrifice would draw all serpents by the power of the chanted mantra into the sacrificial fire. It was not possible to isolate Takshaka alone.
Janamejaya searched for Brahmins with the highest power from meditation and offered the best possible rewards. Many turned the request down for fear of the serpents. It was also known that Takshaka was a close friend of Indra, the king of gods whom they did not want to displease.
Finally, Janamejaya found a few qualified Brahmins to perform the sacrifice. A great platform was made for the purpose as prescribed by the traditional architectural. Several other Brahmins and kings came to attend the great ritual.
Soon the sacrificial fire was lit and offerings were made into the fire with the chanting of powerful Mantras. The power of Mantras was such that snakes from far and near were drawn to it as though pulled by some unknown power. They arrived in large numbers and fell into the flames with no hope for escape.
Stronger serpents resisted the pull for a while. But, soon they also were drawn into the fire to be consumed by the high flames.
King Janamejaya had only one aim, to get Takshaka into the fire. Meanwhile, the great serpent tried to hide here and there. But, the power that was pulling him was such that he found it hard to resist. Finally, he rushed to his friend and mentor, Indra. The king of gods offered him refuge in heaven. But, Takshaka felt the pull even from heaven drawing him gradually towards the sacrificial fire.
In the land of serpents, king Vasuki was in a similar situation. When it was too much for him to bear he rushed to his sister, Jaralkaru. She was married to a Brahmin by the same name. They had a son called Aastika. Young Aastika had spent years in deep meditation and had developed a glow of divinity around him. Jaralkaru, Vasuki’s sister asked her son to save his uncle. Accordingly, the young Aastika set out to the sacrificial ground of Janamejaya.
It was the custom for Brahmins to attend sacrificial rituals like the one performed by Janamejaya. It was also a tradition on the part of those who performed to receive such visiting Brahmins and offer them special seat as per their social standing. When Aastika reached the sacrificial ground all who were present were attracted by the divine glow of the Brahmin and automatically stood up in reverence. Janamejaya thought it be his privilege that such an eminent person sanctified the occasion with his presence. Soon, Aastika entered the sacrificial platform praising the manner in which the ritual was performed. He did not omit to give due credit to the Brahmins who performed it so correctly according to the Sastra (science of rituals) and to the king who arranged all that.
Janamejaya was greatly pleased. He asked the young Brahmin to ask for any gift. Janameja persisted with his request saying that he would consider it an honour to give whatever the Brahmin desired most that was within the king’s powers to offer.
Then, Astika spoke. The only gift that would make him happy was that the sacrifice must stop immediately. By then Takshaka had already appeared in the sky and was about to fall into the fire. Janamejaya was shocked . All his efforts would go waste. He tried to persuade the Brahmin to ask for anything else however valuable that might be. But, Aastika would not budge from his demand. Janamejaya had given his word and he was committed. He also feared the power of the Brahmin to curse him and cause great harm. So, the serpent sacrifice was stopped immediately just before Takshaka fell into the fire.
Vedavyasa had made an appearance at the sacrifice in the beginning. He requested his disciple, Vaisampaayana, to narrate the story of Mahabharata to all who had gathered there. Another disciple of Vyasa by name Soota was also present at the time.
Soota visited various places of pilgrimage from there and finally reached the forest called Naimisha. Many sages were performing a twelve year sacrifice called Satra there. Those assembled asked Soota about the places he had visited and all that he had heard. When Soota mentioned the serpent sacrifice of Janamejaya and the story of Mahabharata that was told there the assembled sages asked him to narrate the story in detail. That was how it was being handed over from one generation to another, as a narration by Soota of what he heard from Vaisampaayana.