After seeing the movie of "City of Ember" I wasn't terribly impressed. Nevertheless, there was enough to the story to intrigue me, and I got the book.
It was a surprise. The book is fairly short, and is essentially straight-up science fiction. Some big, unexplained catastrophe has occurred. This has rendered the surface of the world uninhabitable. Before the end of the world, a handful of experts created an underground city called Ember. They stocked it with food, babies, and elderly couples. The elderly parents were barred from discussing the surface world or anything from outside of Ember. In this way, the children would grow up content with their city and not harbor any regrets for the lost world of the surface. The experts who built the city also left behind instructions on how to leave the city. Instructions to be followed two hundred years later.
Unfortunately, the instructions get lost, the food and supplies are running out, and the electrical power of the city is failng. It is left to two kids to try to get out of the city and try their luck on the surface--that part is very Logan's Run.
I really liked the book. The characters are pleasant and there are many little things and ideas in the book that are clever and keep your attention. That's one of the good things about science fiction. It's the little, clever, what-if ideas that can get thrown in along the way. How would the inhabitants of a dying world behave? How would they react to blackouts, which would be the equivalent of the sun going out in our world? How would they remember foods that are no longer available?
I haven't read any of the sequels yet, but I do recommend the first book in the series.