The book is a rich, exotic saga set in the Sundarbans, an immense stretch of mangrove forest in the Bay of Bengal. It tells the story of a young Indian-American marine biologist, Piyali Roy, who travels to the Sundarbans to study a rare species of river dolphin. There she meets Kanai Dutt, a translator and businessman from Kolkata, who has inherited a journal from his uncle, a visionary who tried to create a utopian society in the Sundarbans. Together, they embark on a journey to the heart of the tide country, where they encounter the beauty and the danger of the natural world, as well as the history and the legends of the people who live there. The book explores themes such as identity, ecology, migration, and the clash between tradition and modernity. It is a captivating and moving novel that has been praised by critics and readers alike.