That diary is in North Kolkata's Banedi house 'Brajdham'. It was there that the retired professor of history Brajmohan Chakraborty committed suicide in the early hours of the morning. Doubt it's not suicide, it's murder. What is the motive of murder? Who or who will kill the innocent Brajmohan? His house is full of Egyptian rare things, how did these things come? Even after the murder, nothing was stolen from that house. Rabindranath? Shantiniketan? Sonajhuri, Bengali nostalgia. Will someone's blood be mixed with that paint? Lagnajita saw the shadow of Kopai while watching the sunset? A mysterious diary whose whereabouts no one knows, yet the diary is there. What is in that diary? In which language is the diary written? Arpita Sarkar's crime thriller- 'Sei Diaryta.' Mystery...one murder after another...a family secret...can Lagnajita Bhattacharya solve this mystery?