A looming disaster in one of the most spectacular environments on Earth sparks a rescue mission unlike any other. When Mexican drug cartels and Chinese traffickers join forces to poach the rare totoaba fish in the Sea of Cortez, their deadly methods threaten to destroy virtually all marine life in the region, including the most elusive and endangered whale species on Earth, the vaquita porpoise. Sea of Shadows follows a team of dedicated scientists, high-tech conservationists, investigative journalists, and courageous undercover agents as well as the Mexican navy as they put their lives on the line to save the last remaining vaquitas and bring the vicious international crime syndicate to justice. This riveting new documentary from National Geographic Documentary Films won the Sundance audience award.