Life is harsh in the Sundarbans, the treacherous islands in the Bay of Bengal where isolated inhabitants live in fear of drowning tides and man-eating tigers. Piya Roy is a young marine biologist, of Indian descent but stubbornly American, who has come here in search of a rare, endangered river dolphin. She enlists the aid of a local fisherman and a translator, and soon their fates on the waterways will be determined by the forces of nature and human folly.