Feluda and his cousin Topshe goes to Lucknow with Topshe's father to spend the Puja trip. They arrived on the home of Dhirendra Kumar Sanyal, a pal of Topshe's father. That night Dr. Shrivastav additionally got here to Dhirendra Kumar Sanyal and tells him about final evening, a thief tried to steal his 'Ring of Aurangzeb' (The Emperor's Ring) which was given to him by Pyarilaal Seth. After the incident Dr. Shrivastav has been afraid and asks Dhirendra Kumar Sanyal to maintain the ring protected. Dhirendra Kumar Sanyal agreed and retains the ring to his house. However sometime the ring goes lacking from there. Then Feluda and Topshe began investigation for the perpetrator. In the meantime, Feluda meets an attention-grabbing individual in physician's neighborhood, Mr. Bonobihari Sarkar. Bonobihari babu has ferocious and toxic creatures like crocodile, African tiger, hyena, rattlesnake, scorpion and black widow spider in his own residence.
