Thiruvilayadal is a collection of stories of Lord Shiva's actions when he appeared on earth in various guises to test his devotee& Four of-these stories are narrated in the film. Sivaji Ganesan portrays the role of Lord Shiva, and Goddess Parvathi is portrayed by Savithri. The story begins when the Lord gives the sacred fruit (brought by sage Narada) to his elder son Ganesha who wins the race with Muruga (circling the universe and coming first) by simply circling his parents as they form his universe. Lord Muruga gets angry and goes to the hill abode of Palani clothed as a hermit. Goddess Parvathi -tries to pacify Muruga, telling him these are small pranks played by his father to make the brothers realize something important that has so far eluded their senses. She narrates the story of Lord Shiva opening his third eye when he visits the city of Madurai in the Pandiya kingdom, in the court of king Shenbaga Pandian (Muthuraman), and makes the great Tamil poet Nakkeeran (AP. Nagarajan), an ego-filled poet of the durbar, realize his shortcomings. In the process, he also helps poet Dharumi (Nagesh), an ardent devotee, to become rich.
She also narrates another episode in which Lord Shiva caused his consort (Goddess Parvathi) to be born as a fisherwoman due to a misunderstanding then he took the form of a fisherman and married her. She narrates another story when the Lord took the form of a woodcutter and seller and taught the great singer Hemanatha Bhagavathar (TS. Balaiah), that pride, even with the greatest talent, is not good. In the end, Lord Muruga realizes his father's divine acts and rejoins his family.
[from the book Pride of Tamil Cinema: 1931 to 2013 by G Dhananjayan, Blue Ocean Publishers, 2014]