Seemanto-heera

Sheemanto heera (The Frontier Diamond) is a detective novella written in Bengali by Sharadindu Bandyopadhyay featuring the sleuth Byomkesh Bakshi and Ajit Bandyopadhyay. Written in 1934, it is the third such work of fiction featuring Byomkesh and is written in first-person narrative, as experienced by Byomkesh's friend, associate, and narrator, Ajit Bandyopadhyay.

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. The diamond had been in the possession of the ruler for generations and a legend had been built around it. According to the legend, if the diamond were to ever be lost, then the line of succession would end. Tridibendran was the sole heir of his line according to the rules of succession where only the eldest son became ruler, but he did have an uncle, Sir Digindra Narayan Roy who was the younger brother of his father. Sir Roy was an established painter and sculptor who worked with mixed media such as plaster of paris. Sir Roy received a lavish monthly pension but since he wasn't heir-apparent, he did not get possession of the diamond. Consumed by greed, he did steal it while the diamond was on display in Calcutta and he replaced it with a fake that looked exactly the same to the untrained eye. He then notified his nephew that he had taken the diamond.

Tridibendra had sought the services of Byomkesh and Ajit to recover the diamond but also requested the utmost secrecy, since he didn't want the press to get wind of this loss. Byomkesh and Ajit returned to Calcutta and checked Sir Roy's house in Ballygunge. The house was very well protected by high walls and a number of guards. Both Ajit and Byomkesh then applied for the post of a secretary to Sir Roy but were detected by the latter and thoroughly humiliated. Not one to lose heart, Byomkesh still boasted that he would find and recover the diamond by the end of the week to which the arrogant Sir Roy took immediate offence. Sir Roy then offered to let him search the house for seven days because he was so confident it wouldn't be discovered. Byomkesh immediately took up the challenge because he realized that this might be the only chance to examine the house and he had already inferred that Sir Roy had hidden it there.