In a sleepy lagoon off the coast of Japan is a highly guarded secret. During the night, Taiji fishermen engage in an unseen hunt for thousands of dolphins. The work is so horrifying, the fishermen will stop at nothing to keep it hidden from the outside world. When a team of elite activists, filmmakers, and free-divers embark on a secret mission to penetrate their cover, the shocking discoveries they find there are just the tip of the iceberg.