The book takes place in the early 1950s during the polio epidemic and is about a girl, Laurie, who uses her amazing storytelling ability to inspire kids in a contraption called the iron lung. (That machine was used to help polio victims breathe by contracting their chests when muscles in that area had become paralyzed.)
As someone who lived during the era I can testify that the details are realistic.
But the important part of the book is the fantasy. Laurie's stories, involving mythological creatures from many cultures, carry the other kids and the reader away from the medical unit and into an exciting other world. As the children participate in the story, they become part of it.
But what will happen when Laurie, herself, gets polio? Can she survive?
Anyone who appreciates the value of Story or who simply wants to be carried away to other worlds will enjoy reading this book.