This book is about this city that lives in darkness and relies on a generator to keep light on the city. The city has been around for more than 200 years. And we soon find out that the generators powers are running out and are about to shut down and if it does this city is doomed. So its up to these two characters to find a way out of the city or fix the generator before time runs out. And before all the lights go permanently shut and everyone drowns in total darkness.