The rich Gulf waters off the coast of Louisiana provide 30% of the nation’s seafood, and harbor some of America’s richest oil reserves. Louisiana’s locals have survived on the region’s oil and fishing industries for generations. But on April 20, 2010, the Deepwater Horizon oil rig explodes, killing eleven people. In the weeks that follow, 200 million gallons of oil gush into the Gulf of Mexico, and Louisiana’s oil and seafood industries grind to a halt. Award-winning filmmaker Joe Berlinger tracks the lives of Louisiana residents living in the aftermath of the largest offshore oil spill in American history. Floyd Lasseigne, a fourth generation waterman, can no longer fish the tainted gulf waters; his illiteracy leaves him few other options for employment. Al and Sal Sunseri, fifth generation oystermen, have not shucked a single oyster since the spill, and face the reality of shutting down their family business. While the obvious signs of the spill fade, marine scientists like Dr. Samantha Joye evaluate the impact; with the aid of a submersible, Dr. Joye travels to the depths of the Gulf, and is shocked by what she finds.