King Mahabali (Onathappan), grandson of pious Prahlad (hero of Holi), returns to earth from the nether world (Patala) once a year. Mahabali worshipped Vishnu and granted his avatar Vamana, appearing as a brahmin boy a boon. The boy asked for three steps of land. Notwithstanding calls for caution from his adviser Shukracharya, Mahabali granted this. The first step covered the earth, the second, the skies. Mahabali realised that the third step would destroy the earth; he therefore sacrificed his head under the foot of Vishnu, which pushed him to Patala, the nether world. Lord Vishnu appeared to the pious Mahabali and granted him a boon - return to earth once a year. Hara hara Mahadev