It's under their skin. In Ghana, Africa, a family is in agony. Parasites called guinea worms are eating through their bodies. While the family gets treatment, a health-care worker hunts for the source of the worms. Can he find it before others become infected? High-interest topics, real stories, engaging design, and astonishing photos are the building blocks of the XBooks, a new series of books designed to engage and motivate reluctant and enthusiastic...