An underground city, only to last 200 years, is now at year 241. The instructions to get out of the city of ember were held in a confined box. The box was to be passed on through the generations of the town mayors. When, one mayor loses the box, his chauffeur finds the box, he doesn't think much of it, and shoves into a closet. Many years later, Poppy Mayfleet found the box, and thinks it is a toy, so she begins to chew it up, leaving the citizens of Ember stranded forever. Lina Mayfleet, and Doon Harrow go on an adventure, to try and solve the mysteries of the box. But while doing so, they learn something about their city mayor, which spreads. Making the citizens of Ember angry. But the mayor, tells the citizens that it was just a rumor, and that Lina and Doon will be going to jail. So Lina and Doon will have to figure out the message, all while having an angry mayor chasing after them.