In Unexplained: Aliens and UFOs, readers in grades 5-9 will explore UFOs and the possibility of alien visitations. Readers are encouraged to use their imaginations and reasoning skills as they discover the history of UFOs, and seek an answer to that age-old question: Is anyone out there? The Unexplained series is designed for readers to be able to flip through until an image catches their interest. Each 32-page book includes spreads that feature a handful of info-packed sentences. Quick tidbits mean the book doesn't have to be read cover to cover, making this series perfect for reluctant readers.