The unprecedented scientific mission to study the lasting impacts of Deepwater Horizon continues. Barely half of the pre-spill dolphin population survives, their calves dying or miscarried. Fish hearts cannot beat properly. Crab burrows leak oily rivulets into wetlands poisoning fish nurseries. Will this ecosystem recover? Will we be able to prevent future oil spills and the ensuing environmental devastation? Narrated by Matt Damon.