Detective Byomkesh and sidekick Awjeet, on the request of Dr. Rakshit, meets Bishupal, a moneylender whose life is under threat from Awbhoy Ghoshal. However, Ghoshal is found dead in a twist of events.
An expensive diamond necklace worth Rs. 57,000 gets stolen from Jeweller Roshomoye Sarkar's house by his servant Bholanath the night before its delivery to Delhi. Byomkesh investigates.
Magno Mainak is a 2009 crime thriller based on the novel of same name by Sharadindu Bandyopadhyay. It was directed by Swapan Ghosal and produced by New Wave Communications. This is the third Byomkesh Bakshi film adaptation. Subhrajit Dutta played Byomkesh while Rajarshi Mukherjee played Ajit. Piyali Munsi, Rupanjana Mitra, Gargi Roychowdhury and Biplab Chatterjee acted in other roles.