The Bengali Detective follows Rajesh over several weeks as he investigates three cases:
Operation Tiger – A corporate client asks Rajesh to investigate counterfeit hair products being sold in local shops. In Central Kolkata, members of Rajesh’s team buy up shampoo they think might be fakes. Later, they raid a shopkeeper’s house but find only original goods; Rajesh concludes, “This raid is a disaster.” A few weeks later, the detectives conduct a raid 160 kilometers east of Kolkata, seizing 700 bottles of fake hair oil. The shopkeeper, Ramesh, claims he didn’t know the goods were counterfeit, but is taken to the Presidency Prison in Kolkata. Rajesh says he has to meet the demands of corporate clients, but concedes that it is the poor, like Ramesh, who suffer by landing in jail.
The Train-Track Murders – Rajesh receives a call from a man named Dibindu, the cousin of one of three young men – Ankur, Tridib and Ratan – whose bodies were found, stripped of clothing and mutilated, on nearby train tracks. Authorities claimed it was a group suicide, but Dibindu believes the case was not properly investigated, and has come to Rajesh for help. In North Kolkata, Rajesh and two investigators visit the mother of one victim and the father of another. Both insist their sons were good boys who had not been in any trouble. At the tracks, Rajesh and his team recreate the placement of the bodies, utilizing photographs to reconstruct the scene. Later, in his office, Rajesh maps out the case details and top suspects on a dry-erase board. He believes the key to solving the case is recovering the three victims’ cell phone records, but the phone company refuses access. Rajesh meets with the Police Homicide Squad Inspector to share his progress in the case, but the inspector says they will not look into procuring the phone records until
after they get the results of the autopsy report, which could stall the case for weeks.
Deepti – A woman in her early 50s, Deepti has come to Rajesh’s office because she suspects that her husband of 24 years has been involved with other women. Rajesh sends a detective to tail the husband; following him to a park, the investigator spots the husband kissing a young woman (their faces are blurred for the camera) and taking her into a nearby apartment building. A few days later, Rajesh meets with Deepti to share the results of his investigation, saying he believes Deepti’s husband is having an affair with the wife of Deepti’s brother – and that he might have a child with a former maid! Deepti says her heart is blank, but at least now she knows the truth. Throughout the film are glimpses of Rajesh’s personal life. He lives with Minnie, his wife of seven years, and their son Guarav. Shortly after they were married, Minnie became ill with diabetes, which has caused her to lose her pigmentation. She is also going blind. As he helps his son get ready for school, Rajesh says the situation has been very difficult for him.