Subarna Sen (Sonada) (Abir Chatterjee) is a professor of history at Oxford University. Returning to India after several years, Sonada meets his nephew Abir (Arjun Chakraborty) and Jhinuk (Isha Saha), Abir's best friend. Abir takes Sonada to their ancestral home in the village of Manikantapur, where Abir’s eccentric but erudite maternal uncle Harinarayan Singha Roy (Goutam Ghose) had recently died under mysterious circumstances. During their visit, they learn of the 350-year-old Mughal treasure of emperor Shah Jahan's second son, Prince Shuja, that is hidden somewhere in that palace. Before his death, Singha Roy had left a clue in his diary to help Abir locate the treasure. At the same time, they discover that the local promoter and political hopeful Dashanan Da (Rajatabha Dutta) also knows about the treasure and is trying to steal it.