On June 7, 2015, two days before Babita left for Gujarat, her native Kokrajhar district, in Assam, saw the second showers of the monsoon. It did two things: it accentua­ted the breathtaking expanse of greenery in her village and forced the khangkrai alari out of their flooded holes in the three bighas of paddy field and farmland her fat­her Theba Basumatary owns, next to their small mud house, in Bamungangaon Bhatipara village.

Six-year-old Babita was always fascinated by these burgundy-coloured, eight-legged crabs. Each monsoon, she would spend hours catching them, putting them in a bamboo basket covered with her mother’s worn dokhana. That evening, Babita demanded khangkrai alari curry. “It’s tedious to catch them, take out their outer shell and legs and cook the edible parts. But I cooked it, thinking who will make it for her in the school hostel,” her mother Champa recalls. Theba, sitting next to her, gets up and walks up to the wall. “Stop discussing all this,” he says to Champa, tears welling up in his eyes.

On...