When Bo Salisbury hurts his ankle playing soccer, doctors think it's a bad bruise. Soon his leg gets worse, and he feels very sick. Will they solve this medical mystery in time?
Series Information Teachers and students can choose from five high-interest topical strands that are based in science, history and social studies. Designed to engage and motivate reluctant and enthusiastic readers alike, Xbooks will help students unlock the power and pleasure of reading.