Byomkesh Hatyamancha

In general, detectives are not allowed to believe in coincidence.

Jim Gordon: "You're a detective now, son. You're not allowed to believe in coincidence anymore" (Dark Knight Rises)

However, the case in this movie is solved using several coincidences. Byomkesh was roaming around Chitpur, he saw Kalicharan. On the contrary, Kalicharan and Kalikinkar pose doubt in viewer's mind; however, our detective is clueless in that front. Kalikinkar is sneaky enough to use paper cuttings to threat Biswanath; however he kept the original paper in his room only to be discovered by the detective.

Moreover, the movie lacks the basic characterization of detective stories; not for a single I feel any suspense. I don't understand the reason behind converting this into a dramatic one.