A brave and resourceful 13-year-old girl who lives with her sister Poppy and their guardian in Sparks, known for her past role as a messenger and her participation in the quest to find the Builders' secret.

A young boy from Sparks who respects Doon and Lina, and exhibits keen observational skills and a love of nature, providing insights into the characters’ motivations.

An antagonist who, along with his family, takes over the abandoned city of Ember, exploiting its resources while proving to have resourcefulness and a desire for control.

A roamer and Washton Trogg’s sister, notable for trading valuable items and unwittingly aiding Lina by facilitating communication and providing shelter.

A boy held captive by the Troggs in Ember, weakened by injury yet courageous, who assists Doon and desires a new life in Sparks.

The original planners and creators of the underground city of Ember, who designed it to be self-sufficient and left behind tools and instructions intended to aid future generations.