Embedded with suspenseful mystery and terrifying thrill, this investigative drama is a sequel to the movie Byomkesh Bakshi (2010), and delves into dangers faced by a talented and insightful detective, Byomkesh. At a critical juncture in his life, Byomkesh is critically ill and is being nursed back to health by his wife, Satyabati (Ushashie Chakraborty), and dear friend, Ajit (Saswata Chatterjee). On medical advice, Byomkesh goes to Dooars to recuperate with his two caring companions. He takes a decided turn for the better with the change in climate, much to the relief of Satyabati and Ajit.
But, as fate would have it, mystery arrives. At Dooars, Byomkesh meets Bengali inhabitants from the local community like Dr. Ashwini Ghatak (Sujan Mukherjee), Prof. Adinath Shome (Pijush Ganguly), Mahidhar Chaudhury (Biswajit Chakrabarty), photographer Nakuleshwar (Arindol Bagchi), police officer Purander Pandey (Kunal Padhy), deputy magistrate Umanath Ghosh (Chandan Sen) and banker Amaresh Raha (Kaushik Sen). They have a get-together at the residence of Mahidhar Chaudhary, where everybody is regaled by the singing of Mahidhar's young daughter Rajani (Swastika Mukherjee).
The flow of the party is somewhat interrupted by the sudden arrival of Falguni Pal, a poor artist, who has the rare talent of painting anyone's portrait after seeing his subject for only a few minutes. In passing, Mahidhar reports that a robbery had taken place at his house a couple of days back. The thief, however, had ignored all of Mahidhar's riches and stolen only a group photograph of Mahidhar with the other Bengali neighbours. Adding to the odd nature of the situation is that all the others who had a copy of that photograph seem to have misplaced or lost the same. The issue is apparently trivial, but, nonetheless, intrigues the ever-alert Byomkesh.
Matters take a more serious turn when there is yet another attempted robbery, this time, at the house of the deputy magistrate, Umanath Ghosh. Falguni Pal, the artist, is murdered in cold blood. In yet another twist, Byomkesh finds out that both Adinath Shome and Ashwini Ghatak are romantically inclined towards the beautiful Rajani.
The strange disappearance of that one photograph leads Byomkesh to believe that someone is trying to remove all evidence of his presence in the locality. And after a series of hits and misses, Byomkesh finds out the killer to be the banker, Amaresh Jha. He was trying to flee with the bank's money and used a fake beard, while in the group photograph he was not wearing it. He stole those photographs and killed Falguni as he drew Amaresh's sketch when he was not in his beard. But, to escape jail, he commits suicide in the local station in the presence of Byomkesh and some others.