Byomkesh Bakshi

Byomkesh solves the mystery by timing the church bells against a witness’s testimony, proving the killer entered the room after Sukumar had returned home. The real culprit is revealed as Phonibhushan, the disabled nephew who felt like a "pity case" and sought to frame Sukumar out of resentment. Phani used the delinquent Makhan to obtain chloroform and stole Satyabati’s needle to commit the perfect crime, even marking Sukumar’s book with a red pencil found in his own possession. Realizing the game is up, Phani commits suicide by leaping from the roof, leaving behind a written confession.The season ends with Byomkesh, Ajit, and a new family member—Satyabati—sharing a meal until a frantic Habul arrives with a new case.

The investigation into Sukumar, a medical student with the anatomical knowledge to kill with a needle, intensifies when Byomkesh finds a marked-up copy of Gray’s Anatomy in his room. However, the red pencil used to mark the murder method is missing. To clear the innocent, Byomkesh and Ajit venture into the city’s red-light district to track down Motilal. There, a woman named Dalim provides Motilal with a solid alibi, confirming he was unconscious from drinking during the murder. Vidhubabu remains convinced Sukumar is the killer after "finding" a new will and chloroform in his trunk, but Byomkesh suspects the evidence was planted. He meets a desperate Satyabati in secret, who confesses she saw a shadow she believed was her brother entering the room at midnight.

Four years later, Byomkesh and Ajit are summoned to the opulent mansion of Karali Babu, a wealthy man found dead at his desk with a steel needle driven into his neck. The motive is clear: wealth. Karali Babu was constantly changing his will, pitilessly pitting his relatives—Motilal, Makhonlal, Phonibhushan, and the siblings Sukumar and Satyabati—against one another. While Vidhubabu focuses on the delinquent Motilal, who fled the house that night, Byomkesh looks deeper. He discovers chloroform marks on the victim and a missing needle from Satyabati’s sewing box. The tension rises as Satyabati, traumatized and beautiful, catches Byomkesh’s eye even as she becomes a person of interest.

After a narrow, high-octane escape from the gambling den, Byomkesh reveals his true identity to a stunned Ajit. He explains that the mess-house itself is the epicenter of the drug nexus. Though Vidhubabu arrests Byomkesh on suspicion, the Commissioner intervenes, allowing the Satyanweshi to set a final trap. Suspecting Dr. Anukul is the mastermind, Byomkesh pretends to accept "medicine" from the doctor intended to silence him forever. In a tense midnight showdown, Byomkesh uses pillows to decoy his own murder, catching Dr. Anukul red-handed with a dagger. The "charitable" doctor is exposed as a ruthless drug lord who murdered the informer and then Ashwini for witnessing the crime.