On the train to Canning, Kanai, a wealthy translator from New Delhi, meets Piya, a young cetologist (a biologist who specializes in marine mammals). They're both headed to the Sundarbans: Kanai is going to the island of Lusibari for the first time in thirty years to deal with a long-lost packet of his late uncle Nirmal's writings, while Piya plans to conduct a survey of the Gangetic and Irrawaddy river dolphins that live in the area. Before they get off at Canning, Kanai invites Piya to come visit Lusibari. Kanai meets up with his aunt Nilima in Canning and discovers that Nilima is still very disturbed by Nirmal's death, which happened twenty years ago.