On Earth Day 2010, the oil rig Deepwater Horizon exploded, flooding the Gulf of Mexico with crude oil and devastating the coastline. Filmmaker Jon Bowermaster returns to the shores of Louisiana five years after the disaster, interviewing a rich cross-section of local denizens – fishermen, scientists, politicians, environmentalists, and oil-rig workers – to uncover the enduring impact of the catastrophe in a dogged investigation narrated by actress Melissa Leo. Has the Louisiana coastline been tainted forever? Will its economy and its ecosystem ever recover?