Tilikum, the 12,000-pound bull orca whose big splashes still climax daily SeaWorld shows, has been implicated in three human deaths, spread over his three decades of forced performances: Two trainers, 20 years apart, and a drifter who in 1999 apparently hid in the park and dove into the wrong pool. Whether Tilikum killed him is unclear—SeaWorld argues the cause of death was drowning and hypothermia-- but what isn't in dispute is that Tilikum bit off the man's genitals and, come morning, was swimming about with the corpse on top of him. Gabriela Cowperthwaite's vital, upsetting Blackfish centers on the 2010 drowning death of Dawn Brancheau, a trainer whom SeaWorld officials have blamed for what they called an accident. Other trainers accuse SeaWorld of having covered up the history of violence in this and other whales. A terrifying mid-film montage of orca attacking trainers is persuasive: These animals are not here for our entertainment. Much of the film is dedicated to their "highly elaborated emotional lives." We hear the cries of orca mothers whose children have been sent off to other parks. Trainers who knew Brancheau pore over video of Tilikum's performance just before her death and narrate the small incidents that might have upset the whale. Brancheau ran low on fish yet still asked Tilikum to perform. The whale seems not to have heard a reward whistle he had been conditioned to relish, and then, frustrated, seems to wallow in that most human of emotions: not being recognized for his work. As he sulks, Brancheau steps near the water. You have rarely seen footage this tense.