Neither Tonia nor her brother Tiger is thrilled when they are cast in a Las Vegas show along with their show-biz parents. Tiger begrudges the time away from his beloved scuba diving, and overweight Tonia feels self-conscious and unable to meet her parents' expectations. Things improve when they meet Chief, an old Indian from a nearby reservation who is also a member of the cast. Tiger is fascinated with Principe, the performing horse, and his handler Ernesto. The boy is sympathetic to Ernesto's bitterness at the contrast of his impoverished childhood in South America with the luxury of Las Vegas. The children and Chief are drawn into Ernesto's plot to blow up a Hoover Dam intake tower as a statement against poverty and injustice. Tonia and Tiger save both themselves and the town's electrical supply, so their show can open as planned. And Tonia finds her niche as a performer, fulfilling her mother's dream. A superficial but satisfying adventure story, with a fast pace and contemporary touches. Details about scuba diving and Las Vegas shows make the rather far-fetched plot more credible. But younger readers may be upset by Ernesto's descriptions of his unhappy past, such as his torture at the hands of government police.