In 2010, a SeaWorld trainer was killed while performing with notorious orca whale Tilikum, who was already responsible for two other human deaths since being captured nearly three decades earlier. In this searing documentary, filmmaker Gabriela Cowperthwaite takes Tilikum’s tragic story as a case study in a larger examination of the practice of keeping killer whales in captivity, using testimony from animal behaviorists and numerous ex-SeaWorld trainers to launch an attack against the practice of keeping these creatures for entertainment. As suspenseful as any thriller, this mesmerizing film offers a harrowing but necessary look into the lives of uncommonly intelligent animals in captivity which challenges us to reconsider our relationship with nature.