The man is Chand Sadagar, a wealthy merchant and devoted Shiva worshipper who flatly refuses to acknowledge Mansa Devi. He considers her a lesser deity. She responds by systematically destroying everything he has — his ships, his sons, his livelihood. He still refuses. Finally, his beloved son Lakhinder is killed by a snake on his wedding night despite elaborate precautions. His daughter-in-law Behula refuses to accept the death. She floats her husband's body on a raft down the river, travelling to the land of the gods to plead for his life.

Behula succeeds. Lakhinder is revived. And Chand Sadagar — stubborn to the end — finally offers Mansa Devi the worship she has been demanding. But he does it with his left hand. A last act of resistance from a man who never fully surrendered.

This story — not Astika, not Kaliya, not Indra's battle with Takshaka — is the story that defines Nag Panchami in Bengal. It is about a goddess who has to fight for her legitimacy, about a father who refuses to bend until he loses everything, and about a daughter-in-law whose love and courage are the actual centre of the narrative. Behula is arguably the greater hero of the Manasamangal than any of the gods in it.

The Mahabharata's Sarpa Satra story also sits behind Nag Panchami. King Janamejaya, to avenge his father Parikshit's death by snakebite, performed a massive snake sacrifice that was pulling every serpent species in the world into the fire. The young Brahmin Astika, himself the son of a serpent princess, stopped the sacrifice with a prayer — and this happened on a Shravana Panchami, which is why that Tithi became sacred to snakes.

Worshipping snakes during this period was, in part, a way of building a psychological relationship with something you feared and couldn't fully control. If you thought of the cobra as a deity rather than a danger, you walked more carefully. You paid attention. You left food at snake pits rather than striking at everything that moved in the grass.

The ecological dimension also matters. Snakes are among the most effective natural controls on rat and rodent populations in agricultural land. A healthy snake population meant a more secure harvest. Nag Panchami, understood through this lens, was partly a festival of agricultural appreciation.