The demon Taraka wins a boon making him unslayable by gods, asuras and rakshasas, and the gods, cursed by Uma to have no offspring, cannot bear a champion. But a spark of Shiva's energy has fallen into the fire, beyond the curse's reach, and it passes from Agni to the Ganga to the six star-mothers, the Krittikas, who nurse the six-faced child Skanda. Made commander of heaven, the war-god slays the unkillable demon and frees the worlds.