The musician duo of Goopi Gayin and Bagha Bayin make a comeback in this sequel, where they are invited to the court of the Hirak Raja (Diamond King), for their musical skills. They have to perform at the kingdom's Jubilee Celebrations. But coming to the kingdom, they use their natural goodness and curiosity to find out that all is not well in the kingdom. There is exploitation of poor farmers and diamond-miners. There are sycophant courtiers and ruthless armies. And there is a mad scientist with this Brain-washing machine. With the help of an upright school-master, Goopi and Bagha set out to correct the evils... with the help of their ghost-given skills, fast thinking and an impish sense of humour.