In July 1956, in a fishing village near the city of Minamata on Japan’s Shiranui Sea, a baby girl named Shinobu Sakamoto was born. Her parents soon realized something was wrong. At 3 months old, when healthy babies can hold up their heads, Sakamoto could not. She grew slowly and began crawling unusually late. At age 3 years, she drooled excessively and still couldn’t walk. Her parents sent her to live at a local hospital, where she spent four years in therapy to learn to walk, use her hands, and perform other basic functions. Early on, several physicians agreed on a diagnosis of cerebral palsy. Yet there were signs that Sakamoto’s condition was part of something much bigger. A few years before her birth, dead fish and other sea creatures had begun appearing in Minamata Bay.