The former citizens of the underground City of Ember now live above ground in a harsh new world. As life becomes more difficult, thirteen-year-olds Lina and Doon return to Ember to find a secret treasure that may help their people. But when they arrive in Ember, they discover that their old home is not quite deserted.
Lina and Doon lie to their elders in order to get away on their adventure, but there are consequences to this action.
Life exists on other planets, though this occupies only the tiniest bit of the plot. Lina sometimes has dreams or visions of a mildly prophetic nature.
Doon fights with the Troggs, and there is a battle against some wolves.
Drug and Alcohol Content
Lizzie suggests that Lina and Doon have run off together to start a family, but this assertion is patently false and quickly dismissed by other characters.
Crude or Profane Language or Content
Washton Trogg calls Doon and Shawgo disparaging names.
The balance between adventure and pathos, mixed with an earnest desire on the parts of Lina and Doon to help their people, makes this a solid tale. As good as the first two Books of Ember, this fourth installment wraps up the tale by giving us a glimpse into the future of the main characters and those who come after them.