When a coin believed to be used by Emperor Jahangir is stolen, the owner, Shankar Prasad Chowdhury, asks Feluda, Lalmohan Babu and Topshe to investigate the theft and find the thief.

Felua and Topshe are invited to the house of Kalikinkar Mukherjee, who wants them to unlock a locker combination uttered by his parrot.

While at a felicitation ceremony, Feluda, a detective, meets Joychand, a simple man who owns a pink diamond. When several buyers set their eyes on the precious stone, Feluda must save the day.

After Ambar Sen's mysterious disappearance a day after he meets detective Feluda, his brother Ambuj Sen asks him for his help to investigate the case.