At Dooars, Byomkesh makes his acquaintance with several 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).
The Bengal Dooars Railway (shortened BDR) was one of the pioneering railway companies that operated from 1894 to 1941, in Bengal province of British India, connecting the Dooars with its junction with Eastern Bengal Railway at Lalmonirhat with locations up to the foot of the Himalayas near the border with Bhutan.