The plot of Sonar Kella deals with a child, Mukul (Kusal Chakravarty), who proclaims that he remembers everything from his past life. In the Bengali film he is referred to as "jaatishwar." He stays up late and draws sketches of Rajasthan. He says he has seen jewels, peacock and a temple. His father decides to take him to take him to Dr. Hajra (Sailen Mukherjee), a parapsychologist. Mukul insists that he lived in Sonar Kella. The way describes his previous birth leads the doctor to decide to take him to Rajasthan so that he can be cured.
On the other hand the newspaper reports on Mukul leads to trouble. Two men, Amiyanath Burman (Ajoy Banerjee) and Mandar Bose (Kamu Mukherjee), play foul as they think that Mukul knows about some hidden treasure as he talks about forts and gems. They plan to kidnap Mukul but their attempt fails as Mukul had already left with Dr. Hajra and they pick up another boy by the same name. Mukul's father is panicked by such an incident. It is then that Feluda enters the plot of Sonar Kella. The worried man approaches Feluda for looking after his son's safety and finding about those men who are a threat to Mukul.
On the other side of the story the two villains follow Dr. Hajra and Mukul. These are the same people whom the doctor had sent to jail earlier. However this time with new names and get ups they befriend Dr. Hajra and Mukul. While checking out the local sights they push off Dr. Hajra from a cliff and start spending time with Mukul. On the other hand Feluda (Soumitra Chatterjee) and his nephew Topshe (Siddartha Chatterjee) proceed with their investigations and get on a train for Rajasthan. On their trip they meet Lalmohan Ganguly or Jatayu (Santosh Dutta), a popular writer. The trio then checks into the same accommodation where Burman impersonating as Dr. Hajra and Mandar Bose are staying with Mukul.
One night Burman hypnotise Mukul and comes to know that the fort is in Jaisalmer. Feluda and gang also find out that the Sonar Kella has got nothing to do with gold. It is the hue of the fort, a yellow fort that Mukul refers to as the Sonar Kella. They hurriedly come back to their accommodation only to find that Berman has left with Mukul already for Barmer. Mandar Bose provides this wrong information to mislead them. Feluda is not convinced and checks the register. He is shocked to find out that Dr. Hajra has misspelt his name. Now Feluda understands the whole game plan. He sets out for Jaisalmer. The real Dr. Hajra is still alive although he is terribly wounded. He too follows them. Mandar Bose tries all the tricks up his sleeves to stop Feluda from reaching Jaisalmer.
However Feluda, Topshe, Jatayu and Dr. Hajra finally reach Jaisalmer and find out Mukul and Burman. Mandar Bose gets killed as he falls from train. Sonar Kella ends on a positive note with Burman captured, Mukul becoming his normal self and all of them go back to Kolkata.
Sonar Kella is worth watching for its immensely talented star cast. As is the case with Satyajit Ray movies each and every actor is perfect in his or her role. Even today for any Bengali Feluda and Soumitra are synonymous. One of the best attractions of Sonar Kella is Jatayu. The way Santosh Dutta enacted the character it made Jatayu as much popular as Feluda. After the death of Santosh Dutta Ray stated that it was impossible for him to make Feluda movie without Santosh Dutta. The cinematography of Sonar Kella is equally impressive in the way the vibrant landscape of Rajasthan is shot.
Sonar Kella received a number of awards that include: