The Marvel titles in Disney's World of Reading line are designed to offer reluctant readers, specifically boys, books that they will want to read by featuring characters they love. The series is broken into three levels that invoke the rigorous training courses that their favorite Marvel heroes must engage in to perfect their superpowers. In reading this series, boys will perfect their own power to read. The Story of the X-Men tells the story of how Marvel's most popular mutants became the Uncanny X-Men! ,