Chiriyakhana

A brilliant private detective who accepts Nishanath Sen's case and investigates murders across Golap Colony. He disguises himself as a Japanese horticulturist named Okakura and uses a voice recorder to document interrogations, enabling meticulous deduction.

Byomkesh's loyal friend and narration partner, who accompanies him in disguise and assists with interviews aboard the investigation.

An actress central to the mystery; later revealed to be Banalakshmi, the wife of Dr. Das, who underwent plastic surgery to alter her appearance.

A physician and sitarist whose alibi is exposed by a taped recording; revealed as the killer who used Sunayana's disguise to hide his crimes and steal valuables.

Nishanath Sen's nephew; a potential heir and love interest in the tangled web of relationships, entangled with the estate and Sunayana's past.

Sen's employee whose actions and motives come under scrutiny as the investigation unfolds.

A resident of Golap Colony whose ties to the case complicate the lineup of suspects; his household is part of the inquiry.

A deaf-mute witness who observed the crime and becomes a tragic catalyst for the investigation as similar murder methods reappear.

An employee who confesses about the relationships surrounding Sen, helping explain the motive behind the murders.

A sheltered woman among the Golap Colony residents; her role contributes to the case's shifting motives and possibilities.

The police inspector who requests Byomkesh's help, pushing the investigation forward.