Blackfish tells the story of Tilikum, a performing killer whale that killed several people while in captivity. Along the way, director Gabriela Cowperthwaite compiles shocking footage and emotional interviews to explore the creature’s extraordinary nature, the species’ cruel treatment in captivity, the lives and losses of the trainers and the pressures brought to bear by the multi-billion dollar sea-park industry. This emotionally wrenching, tautly structured story challenges us to consider our relationship to nature and reveals how little we humans have learned from these highly intelligent and enormously sentient fellow mammals.