What will they think of next? That's the sense of wonder generated by this entry in the Beyond 2000 series, which looks ahead to the day when tiny submarines patrol arteries, destroying hostile germs and fat buildups and other tiny devices digest garbage on waste dumps. These advances might come through the science of nanotechnology, which involves building structures and machines from individual atoms and molecules. Darling looks at the history of miniaturization and gives a detailed explanation of how computer microchips are made. Most exciting is the research involved in creating microscopic versions of machines such as gears, pumps, and motors, aptly known as micromachines. The author has a real girl for writing about complicated technology; he presents the potential for both good and evil that can arise out of such scientific leaps.