The movie merges two stories of Sharadundu Bandopadhyay, "Agnibaan" and "Uposonghar." The film starts with the hint of another story, "Satyanweshi" where young Byomkesh catches the head of a cocaine racket who is now seeking revenge. On the other hand, a young girl dies in mysterious conditions having a match stick in her hand. One Kokonad Gupta, who claims to be a fan of Byomkesh, gifts him a matchbox.