It is told that once three demons, by their devotions to Lord Shiva, and their austerities, won the favour of the lord, and he decided to grant them a boon. They requested that they could only be killed if they were all three together and struck by a single arrow. Lord Shiva granted this, and the demons, feeling invincible, went to different lands, built forts and palaces, and began to conquer the world.

The behaviour of the demons was bloodthirsty and cruel, and soon complaints and prayers began to rise to heaven, begging that the demons should be stopped. The other gods appealed to Lord Shiva to slay the demons, but he pointed out that they continued to worship him, and were therefore under his protection.

Then Lord Vishnu took the form of a sage and went to the demons and gave them false teaching, persuading them that, since they were now invincible because of the boon, they no longer needed to worship Shiva. As their minds were already in darkness, it was not difficult to convince them, and so they ceased their prayers and puja.

Again the gods went to Lord Shiva, now telling him that the demons were no longer his devotees, and that he should purify the earth from their cruelty. When Shiva agreed, all the gods came hurrying to help in the destruction of the demons. The earth became his chariot, Lord Brahma became his charioteer, Lord Vishnu became the single arrow, fire and death became the wheels of the chariot – all the gods wished to help.

The demons, forgetting the condition of their boon, came together to meet the attack, and then Lord Shiva showed that he did not need the help of the other gods, and taught the universe about purification – for he did not shoot the arrow of Lord Vishnu. He simply smiled, and the power of his smile shot forth like an arrow, burning the demons to ashes and purifying the world.