It is the first film adaptation of Ray's famous sleuth Feluda and was followed by Joi Baba Felunath, in English The Elephant God.
The film begins with a school-boy Mukul Dhar (Kushal Chakraborty), who is said to be able to remember events of his previous life, and soon receives media attention.
Mukul always remains sombre and paints peacocks, forts, camels and battlescenes at midnight; he mentions that he lived in the Golden Fortress (Sonar Kella) and that their house had many gems.
Dr. Hajra decides to take Mukul on a trip to Rajasthan, famous for forts, historical importance and desert landscape.
Meanwhile, Burman and Bose kidnap Mukul and push Dr. Hajra off a cliff to his presumed death at the Nahargarh Fort in Jaipur.
By chance, his eye falls upon the card of Dr. Hajra; an idea flashes in his mind and he rushes to check the register of the circuit house and finds that it is signed as 'Hazra' not 'Hajra'.
While on their way to railway station, Bose strands the trio (Feluda, Topshe, and Jatayu) on the highway by pucturing the tyre of their car.
They rush to the fort where they find Burman searching for the treasure where Mukul recalls his home of previous life.