The Summary
At the end of mankind on Earth, the scientists build a self-sufficient underground city for a few people in order to preserve the human race for two hundred years. They leave also instructions for the future generations to return to the surface of the planet in a steel box that should be kept by the mayors through the generations. However, the instructions are lost and the inhabitants stay in the city that is completely deteriorated. The power generator has problems and the blackouts are longer and more frequent and the city is running out of food that needs to be rationed. On the Assignment Day, the teenagers Lina Mayfleet and Doon Harrow are assigned to work with the pipework and as messenger, but they swap their job positions. Luckily, Lina found an "Instruction for Egress" and decided to show and ask Doon with a few others to help reconstruct the letter. Right after they succeed, they found a river with a small boat, so they went on the boat. There were a lot of "obstacles" on the way but they finally made it. The river leads them to a really old journal contains all the important information about the City of Ember. Later on, they spent hours on a really high and straight-up climb and reached the top and discover the whole outside world. And through chains of situations, they found a cave leading to a cliff that shows the underground city miles below. Last but not least, Doon took his shirt, wrapped around a rock with the instruction tied to it and threw it down to the city to leads other people up to a better place. The book ends with Mrs. Murdo found the note and was unwrapping it.