Journalist Kirby offers another passionate industry exposé (after 2005’s Evidence of Harm), focusing on SeaWorld Orlando’s popular orca display and its costs in happiness and safety for both the animals and the humans who care for them. The main issue at hand is trainer Dawn Brancheau’s death, caused in 2010 by the orca and star SeaWorld attraction Tilikum, but Kirby’s painstaking account takes its time before arriving at this central tragedy. In addition to the long history of previous violent incidents involving captive killer whales, Kirby teaches readers more than they ever expected to learn about such subjects as marine park management and orca social dynamics. This comprehensive background can sometimes be more diligent than engrossing, but the narrative goes into high gear with its concluding confrontation between what Kirby portrays as SeaWorld’s corporate juggernaut, and the scrappy “anti-cap” (captivity) activists. From this latter camp, the book gives the most attention to disillusioned former trainer Jeff Ventre and, taking center stage as the story’s heroine, marine biologist Naomi Rose. Kirby’s exhaustively researched chronicle offers the definitive look at its subject, coming down squarely on Rose’s side to conclude that the human use of orcas for entertainment does neither species any favors. Agent: Todd Shuster, Zachary Shuster Harmsworth. (July)