Abby and Derick have been accepted to the most prestigious secondary school in the world—Cragbridge Hall. Due to the inventions of their grandfather, Oscar Cragbridge, they will be able to experience history in 3D, use their minds to literally project visual interpretations of classic literature, and become animal avatars for zoology.But when their grandfather and parents go missing, Abby and Derick must follow clues Oscar left for them that will reveal a dangerous secret. Along the way, they discover there is much more to one of their grandfather's inventions than anyone has ever dreamed. Saving their family will take all of Derick's mind and Abby's heart as they come face to face with a crazed scientist who desperately seeks to change the past. If they fail, the world—past and future—will never be the same.This book is a page-turning, time-travel adventure that teaches powerful lessons about choice and consequence, believing you can do hard things, and valuing your history.