The title refers to a hidden area in a small Japanese town where the dolphins who are unable to be sold are led to be slaughtered for their meat. This Oscar nominated documentary focuses on this town's cruel practices, but introduces to other ways in which dolphins are mistreated around the globe. We learn about how dolphins suffer in captivity and how the largest whale protecting group in the world does not include porpoises or dolphins due to Japanese interests in their hunting and killing. We are also given beautiful footage of dolphins in the wild as well as in captivity. One of the people who guides us through this well-made doc is Ric O'Barry, a former dolphin trainer who helped train Flipper for the popular TV series.After realizing the dangers of captivity, he has spent the last thirty years fighting back against an industry he worked for. You can actually sense the remorse and see the sadness in his eyes as he reflects on his days as a trainer. Yes, there are also interviews of eco-nuts who think dolphins are smarter and more important than humans, but overall this is a harrowing film, especially in the last ten minutes when the filmmakers find their way to the deadly cove and expose the world to the blood red waters where dolphins are being slayed.