 Unlike most of the novels featuring Byomkesh, this one does not involve any violent crime or major plot twists.The story revolves around the theft of a priceless heirloom, the "Seemanto-heera" or "Frontier Diamond", belonging to the heir of the Roy clan, one of the minor rulers of North Bengal.Byomkesh and Ajit have been invited by the current heir, a young Rai Bahadur Tridibendra Narayan Roy to recover the diamond.