Bir Pratap Chowdhury is a corrupt yet valiant ACP in Kolkata who walks a fine line between duty and danger. He aims to bring down the dreaded Joykrishna Ganguly, but his mission ends in tragedy when Bir Pratap loses his life and Joykrishna is snatched away by Bir Pratap’s own allies, Biswas and Mukherjee. The news hits hard: the Home Minister Ramkrishna Ganguly worries about the fate of the case, while Bir Pratap’s mother collapses from the shock and is rushed to the hospital. Ramkrishna vows to nail Joykrishna or resign if he fails, rallying the public with a promise that echoes through the city.
In the present day, Kolkata follows a different current. Jeetu, a doppelgänger of Bir Pratap, is a carefree dreamer who longs to wear the police uniform, yet his path to a badge remains blocked. He lives with his brother-in-law Bhojon Bose, a CI who serves as a constant reminder of how hard it is to break in. To change his fortune, Jeetu approaches Anjali, Sayantika Banerjee a charismatic figure who claims to deal in gemstone-based astrology and can supposedly alter a person’s destiny. In truth, Anjali is a con artist, but she still lends Jeetu a ring—one she claims has magical powers, though it really does nothing of the sort.
Jeetu soon finds himself entangled in real police work when he helps his brother-in-law capture a dangerous convict, earning some attention but little credit. Bhojon grabs the spotlight at the press conference, leaving Jeetu feeling overlooked. The twist comes when Bhojon reveals he had previously rejected Jeetu’s dream of joining the police academy. Ramkrishna, watching the news, sees potential in Jeetu and orders him to impersonate Bir Pratap to imprison Joykrishna Ganguly. Jeetu accepts and travels to Selimpur, donning the façade of Bir Pratap and freeing Joykrishna from Biswas and Mukherjee. He escorts the gangster to Ramkrishna, only for Ramkrishna to betray him in a single, brutal stroke, stabbing him and letting the truth spill out: Joykrishna is actually Ramkrishna’s brother. Ramkrishna vanishes, leaving Jeetu reeling. Biswas and Mukherjee rescue Jeetu, rush him to the hospital, and finally reveal Bir Pratap’s past to him.
The backstory unfolds with a procedural sting. Biswas and Mukherjee are appointed as Bir Pratap’s aides by the Anti-Corruption Bureau’s commissioner, Ranjit Kumar Kapuria, to gather evidence of Bir Pratap’s corruption. Bir Pratap is constantly shadowed by Inspector Pradip Kumar Sarkar, a crooked cop who rides with him wherever he goes. A crucial kidnapping plot threads Joykrishna Ganguly with the murder witness Gopal, who could seal the case against the gang. Bir Pratap strikes a deal with Joykrishna for a sizeable ransom to hand over Gopal, deepening his entanglement in crime as he fights to keep the truth buried.
Amid this moral maelstrom, Bir Pratap finds love. He falls for Shruti, a philanthropist who runs the Aasha Foundation and shares his flashes of tenderness. A raid on his house—conducted by Biswas and Mukherjee, who also find the flash drive listing other cops—turns up critical pressure and fuels distrust. Shruti’s faith in Bir Pratap trembles as she witnesses the brutality behind the badge. Bir Pratap’s uncle, Rajat Pratap Chowdhury, reveals a heartbreaking motive tied to his dying mother Nilanjana Pratap Chowdhury: she longed to see her son become a cop, and Bir Pratap’s failed selection becomes the catalyst for a vow. He spends 10 lakh rupees to secure a seat, but receives a bribe-filled reality instead; the next morning, Bir Pratap’s mother dies, having believed the path to a badge was closed. This tragedy hardens him, and he resolves to pay the costs of corruption on behalf of noble candidates who deserve a fair chance. Soon after, Bir Pratap and Shruti become engaged.
The past grows darker as Bir Pratap eliminates Debkrishna and arrests Joykrishna on charges of killing ACP Avinash, with Gopal standing as the chief witness. But Pradip Kumar Sarkar betrays him, selling the evidence and intelligence about Gopal for a bribe. Joykrishna’s gang retaliates by killing Bir Pratap’s uncle and assaulting Bir Pratap and Gopal at the court, while Shruti and Gopal perish in the ensuing chaos. Bir Pratap escapes, rekindling a brutal resolve: he kidnaps Joykrishna from P.K.’s custody with Biswas and Mukherjee at his side, and then crashes in the hills, his car exploding and killing him.
In the present, the truth begins to surface. Jeetu commits to setting things right. Ramkrishna fabricates evidence against the sitting Chief Minister of West Bengal, alleging that he was backing Joykrishna all along; the Chief Minister is forced out, arrested, and Ramkrishna’s bid for power gains momentum. Yet Joykrishna, though imprisoned, continues to run the crime syndicate from inside the system. Jeetu returns to duty and confronts Ramkrishna, seeking to protect his own post. He forms a fragile alliance with Ramkrishna’s PA, Bijoy Sanyal, and is drawn toward Anjali once more, reconnecting through a clever ruse involving a ring-based camera system. The ring, a compact device hidden in a fake gemstone, captures audio and becomes a weapon to broadcast Ramkrishna’s corruption to the media. Ramkrishna and his brother go underground in a panic, and the chaos widens to include Anjali, Biswas, Mukherjee, and Bhojon’s family.
Ranjit Kumar Kapuria, watching the entire cascade, uncovers the jaw-dropping truth: Jeetu and Bir Pratap are the same person. As the car explosion rewinds in memory, Bir Pratap falls from the vehicle into a freight carrier and slips into amnesia. Bhojon’s wife has long searched for her lost brother Jeetu, and Bhojon uses this gap to pass Bir Pratap off as Jeetu, hoping to spare her pain and to shield himself from financial ruin. Kapuria warns that exposing the truth could be deadlier than any crime.
The climax erupts as Jeetu storms Joykrishna’s fortress, defeats the criminal mastermind, and brings Ramkrishna to justice. Biswas, Mukherjee, and the others decide not to shatter Jeetu’s fragile peace by revealing the full truth about his identity and the losses of his uncle and fiancé. In the end, Jeetu marries Anjali, and, though he continues to pose as Bir Pratap Chowdhury, Kolkata has its quiet, uneasy hero—a man who has walked through duplicity and memory loss to restore a semblance of order to a city fed up with corruption.
