The film begins with a school-boy Mukul Dhar, who is said to be able to remember events of his previous life, and soon receives media attention. Dr. Hemanga Hajra, a parapsychologist, offers his help, believing it might help him in his own research. Mukul always remains sombre and paints peacocks, forts and scenes of battle at midnight; he mentions that he lived in the Golden Fortress 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. Two seasoned fraudsters, Amiyanath Burman and Mandar Bose, plan to kidnap Mukul to capture the treasure. Their first attempt at the kidnapping fails when they pick up another boy, also named Mukul, from the same neighborhood. Alarmed by this, Mukul's father engages Feluda, a private investigator, to protect his son. Feluda leaves for Rajasthan along with Topshe or Tapesh, following Dr Hajra. On their way, they meet Lalmohan Ganguly, a.k.a. Jatayu, a popular thriller-writer. Meanwhile, Burman and Bose kidnap Mukul and push off Dr. Hajra off a cliff at the Nahargarh Fort in Jaipur. Burman impersonates as Dr. Hajra and Mandar Bose as a globe-trotter. Dr. Hajra survives the fall and begins to pursue them. Feluda arrives in Jodhpur Circuit House and meets Burman, thinking him to be Dr. Hajra. Feluda begins to suspect Mandar Bose based on his clothes and his accent. Feluda even suspects "Dr. Hajra's" conduct as he appears lackadaisical in his research. Mukul keeps saying he is followed by a "bad man". Burman hypnotizes Mukul, who says that the Golden Fortress is in Jaisalmer. Dr. Hajra reaches the same conclusion by learning about the history of the Fort of Jaisalmer from a police inspector. Feluda learns that the Jaisalmer fort is made of yellow limestone, giving it a golden glow. Mandar Bose tells Feluda that Burman has already left with Mukul for Barmer. Feluda suspects foul play but cannot be sure. 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'. He is now sure about the man masquerading as Dr Hajra, and leaves for Jaisalmer by car. Mandar Bose strands Feluda, Topshe, and Jatayu on the highway. Feluda takes a camel caravan to the nearest train station, from which he takes the next train to Jaisalmer. At night, In the train, Mandar Bose tries to stab Feluda, who anticipated the attack and almost nabbed him; eventually, Mandar Bose falls out of the train. The three reach Jaisalmer along with Dr. Hajra. They rush to the fort, where they find Burman and Mukul searching for the treasure. Feluda confronts and captures Burman, telling him that there never was any treasure. They find that Mukul is cured, and return to Kolkata.
Characters
Prodosh Chandra Mitter aka. Feluda
Tapesh Ranjan Mitter aka. Topshe
Lalmohan Ganguly aka. Jatayu
Sidhu Jyatha
Mukul Dhar
Mandar Bose
Amiyanath Burman
Dr. Hemanga Hajra
Dibbhojuthi Paul
Binay Mitra
Cast in the film
Soumitra Chatterjee as Feluda
Siddartha Chatterjee as Topshe
Santosh Dutta as Jatayu
Kushal Chakraborty as Mukul Dhar
Shailen Mukherjee as Dr. Hemanga Hajra
Ajoy Banerjee as Amiyanath Burman/Bhavananda/fake Dr Hemanga Hajra
