The people of Ember live in a place and time in the future after there has been a threat to our world. They live in a place of little color, black skies, and only artificial light. None of them have any memory or knowledge of a time or place that would be any different. Up until the time of this story, the citizens of Ember has been content in their world, but of late, there have been frightening developments. There appear to be more and more shortages of everything; people going to shop for food or supplies are often told that the items they want are no longer available, and there is no reason to believe new supplies will become available. Additionally, the generator which powers the light source for the city is breaking down more and more frequently, plunging the city into total darkness. 
 Lina and Doon, two children who have just completed their schooling and started working in the city are increasingly aware and concerned about the situation in Ember. Together they search for a way to help their city, or to find a way out. 
 This book is one that keeps the reader hooked to see what will happen next. The characters are ones that become more familiar and developed as the book progresses so that the reader cares about seeing what happens to them. There is a good deal of allusion and allegory throughout this book, and that does bring an interesting aspect to the book for more experienced/older readers.