When Brihaspati, preceptor of the gods, foremost in all branches of learning, and venerated alike by the gods and the asuras, came to his court, Indra did not rise from his seat to receive the acharya or ask him to be seated and failed to do the customary honors.
In his great conceit, Indra persuaded himself to believe that the sastras allowed him as a king in court the prerogative of receiving guests seated. Brihaspati was hurt by Indra's discourtesy and, attributing it to the arrogance of prosperity, silently left the assembly.
Without the high priest of the gods, the court lost in splendor and dignity and became an unimpressive gathering.
Indra soon realized the foolishness of his conduct and, sensing trouble for himself from the acharya's displeasure, he thought to make up with him by falling at his feet and asking for forgiveness.
But this he could not do, because Brihaspati had, in his anger, made himself invisible. This preyed on Indra's mind.
With Brihaspati gone, Indra's strength began to decline, while that of the asuras increased, which encouraged the latter to attack the gods. Then Brahma, taking pity on the beleaguered gods, advised them to take unto themselves a new acharya.
Said he to them: "You have, through Indra's folly, lost Brihaspati. Go now to Twashta's son Visvarupa and request that noble spirit to be your preceptor and all will be well with you."
Heartened by these words, the gods sought the youthful anchorite Visvarupa and made their request to him saying: "Though young in years, you are well versed in the Vedas. Do us the honor of being our teacher."
Visvarupa agreed, to the great advantage of the gods for, as a result of his guidance and teaching, they were saved from the tormenting asuras.
Visvarupa's, mother was of the asura clan of daityas, which caused Indra to regard Visvarupa with suspicion. He feared that because of his birth, Visvarupa might not be quite loyal and his suspicion gradually deepened.
Apprehending danger to himself from this descendent of the enemies of the gods, Indra sought to entice him into error with the temptresses of his court and so weaken him spiritually. But Visvarupa did not succumb.
The artful and seductive blandishments of Indra's glamour girls had no effect on the young ascetic. He held fast to his vow of celibacy. When Indra found that his plan of seduction failed, he gave way to murderous thoughts and one day killed Visvarupa with the Vajrayudha.
The story goes that the world suffers vicariously for this great sin of Indra. And, as a result of it, parts of the earth turned alkaline and became unsuitable for cultivation and women came to be afflicted with the physical troubles and uncleanness peculiar to them. The frothing of water is also attributed to this.
Twashta in his great rage and grief at Indra's cruel killing of his son and, desirous of avenging his death, performed a great sacrifice. And out of the sacrificial flames sprang Indra's mortal enemy Vritra.
Twashta sent him against the chief of the gods, saying: "Enemy of Indra, may you be strong and may you kill Indra." A great battle raged between the two in which Vritra was gaining the upper hand.
When the battle was going against Indra, the rishis and the gods sought refuge in great Vishnu who offered them protection and said to them: "Be not afraid. I shall enter Indra's Vajrayudha and he will win the battle in the end." And they returned in good heart.
They went to Vritra and said to him: "Please make friends with Indra. You are both equal in strength and valor."
Vritra respectfully answered: "O blameless ones, how can Indra, and I become friends? Forgive me. There cannot be friendship between rivals for supremacy. Two great powers cannot coexist as you know."
The rishis said in reply: "Do not entertain such doubts. Two good souls can be friends and their friendship is often after hostility."
Vritra yielded saying: "Well, then, I shall cease fighting. But I have no faith in Indra. He might take me unawares. So I seek this boon of you, namely, that neither by day nor by night, neither with dry weapons nor with wet ones, neither with stone nor with wood, nor with metals, nor with arrows shall Indra be able to take my life."
"So be it," said the rishis and the gods.
Hostilities ceased. But soon Vritra's fears were confirmed. Indra only feigned friendship for Vritra but was, all the time, waiting for a suitable opportunity to slay him.
One evening, he met Vritra on the beach and began to attack him in the twilight. The battle had raged for a long while when Vritra praising the Lord Vishnu, said to Indra: "Meanest of the mean, why do you not use the unfailing Vajrayudha? Hallowed by Hari, use it against me and I shall attain blessedness through Hari."
Indra maimed Vritra by chopping off his right arm but, undaunted, the latter hurled with his left band, his iron mace at his assailant who thereupon cut down his other arm also. When Indra disappeared into the mouth of Vritra, great was the consternation of the gods.
But Indra was not dead. He ripped Vritra's belly open and issuing forth went to the nearby beach. And directing his thunderbolt at the water hurled it so that the surf flew and hit Vritra. Vishnu having entered the foam, it became a deadly weapon and the mighty Vritra lay dead. The long battle thus ended and the afflicted world heaved a sigh of relief. But to Indra himself, the end of the war brought only ignominy because his victory was secured through sin and deceit and is went into hiding for sheer shame.
Indra's disappearance caused the gods and the rishis great distress. For a people without a king or a council of state to govern them cannot prosper. So they went to the good and mighty king Nahusha and offered him the crown.
"Forgive me, I cannot be your king. Who am I to aspire to the seat of Indra? How can I protect you? It is impossible," he humbly objected. But they insisted, saying: "Do not hesitate. Be anointed our king. All the merit and potency of our penance will be yours and be an addition to your strength. The power and the energy of everyone you set your eyes on shall be transferred to you and you will be invincible." Thus over-powered, he agreed. Revolution is no new thing. This story shows that, even in the world of the gods, there was a revolution leading to Indra's dethronement and Nahusha's installation as king in his stead. The story of Nahusha's fall is also instructive.