In the early hours of March 24th 1989 the Exxon Valdez oil supertanker runs aground in Alaska. It discharges millions of gallons of crude oil. The incident becomes the biggest environmental catastrophe in North American history. In a flash, dramatic images shoot across the planet. They show thousands of carcasses of dead seabirds and sea otters covered in oil. A thick black tide rises and covers the beaches of once-pristine Prince William Sound. For twenty years, Riki Ott and the fishermen of the little town of Cordova, Alaska have waged the longest legal battle in U.S. history against the world's most powerful oil company - ExxonMobil. They tell us all about the environmental, social and economic consequences of the black wave that changed their lives forever. This is the legacy of the Exxon Valdez.