Byomkesh is having a lean season when he literally has no work Suddenly one day a Lady named Nonibala Devi (a lady with extremely hard features and rather manly looking) comes to him and asks him to help her son Prabhat (someone whom she looks upon as her own son though not her own).It seems that from his childhood she had brought him up when someone had given birth to him and passed way, but his father had deserted him. However a gentleman called Anadi Haldar had liked him one day when he had met Prabhat due to work related purposes and had treated him as his own son from there onwards.Nonibala stays in Anadi’s house with Prabhat, the occupants being Keshtobabu, an old friend of Anadi who loves to drink and depends on Anadi on his four square meals, Nripen, Anadi’s secretary.Anadi has a couple of nephews, Nemai and Netai who were after his property.Byomkesh tells Nonibala that he cant help her but asks her to leave the address of Prabhat’ shop. After a couple of days, Byomkesh and Ajit pay a visit to Prabhat’s shop and meet him where he recognizes Ajit.He seems to be a subdued, shattered individual who doesn’t have anything to look forward to in his life because of his broken engagement to Shiuli, a bar dancer whom he loves dearly.Byomkesh pays a visit to Anadi’s house in disguise and finds him to be an irritating man. One day Keshto comes at night to Byomkesh’s house to inform him that Anadi has been murdered.Byomkesh immediately goes to Anadi’s house and decides to investigate the case. From further investigations, he comes to know that one of the nephews had taken a room on rent in a hotel opposite Anadi’s house to keep an eye on his uncle. He also comes to know the nephew had seen the murder take place , but had not seen the murderer. One day Ajit receives a call from Keshtobabu saying that he wants to meet Byomkesh immediately, but at theta time he is Patna.Keshtobabu somehow manages to reach Byomkesh’s doorstep only to have been dead in Ajit’s arms as someone has stabbed him. Meanwhile Prabhat decides to sell his hop and go away.Byomkesh decides to buy it. On the eve of Independence Day at night, Byomkesh and Ajit wait for Prabhat to arrive. As soon as he arrives and tries to take away a few books, he is caught red handed by Byomkesh.It seems that the books have notes bound in them.Anadi had made a huge amount of black money-around 20 lakhs during World War II and he had kept the money in several books of his by binding the money in those books. It is further revealed that Keshtobabu had been killed by Batul, an arms dealer (who also used to visit Byomkesh) because he was blackmailing Batul as he knew Batul had given a rifle on rent to Prabhat who had killed Anadi.Nonibala had also seen Prabhat commit the crime, but her maternal instincts had prevented her from saying anything.Prabhat also comes to know that Anadi was his real father and everyone (Anadi and Nonibala) was aware of the fact.