Save the Whales is so last century. Dolphins, according to the new Academy Award-winning documentary The Cove, are what really need saving now.

The film profiles Ric O’Barry, a former dolphin trainer who captured and trained the dolphins for the 1960s show Flipper. It was during that time when O’Barry realized the inherent cruelty of his job and what the dolphins went through as domesticated animals, so he set out on a lifelong crusade against dolphin hunting and keeping them in captivity.

There is one coastal town in Japan, we learn, that is notorious for herding dolphins into a secretive cove to capture them for use in the dolphin entertainment industry (SeaWorld, among other places) or simply to slaughter them to sell for meat. The fishermen who do this maintain a paranoid level of secrecy around the cove, making sure no one can see what actually goes on.

However, a team of divers and activists from the Oceanic Preservation Society teams up with O’Barry to sneak behind the iron curtain and expose the nefariousness once and for all. Using a kind of subterfuge the creators of Ocean’s Eleven would be proud of, they install small cameras in fake rocks and on the cliffs surrounding the cove to try to capture on film the merciless killing the small Japanese fishing town is so eager to disguise.

The Cove is a nail-biting thriller disguised as an environmental call-to-arms. The scenes of the team breaking into the cove, eluding guards and avoiding detection, are better than anything you’ve seen in any recent spy movie. The new information we learn, too, about how dolphin meat makes its way onto the market without consumers knowing it, and how Japan curries favor from other coastal nations in order to avoid controversy is fascinating.

The film is ultimately one-sided; you know who you’re supposed to root for. Yet once you’ve seen the footage of the actual slaughter, rooting for the dolphins becomes the easiest thing you can possibly do. It’s not for the faint of heart, but The Cove deserves to be seen.