Central to the plot are the elves’ many powerful abilities. Sophie, Alden, and Fitz are Telepaths who can read and send thoughts. Dex is a Technopath: He communicates with machines. Keefe, an Empath, often reads Sophie’s emotions and kids her about them. Abilities tend to manifest during adolescence, and Foxfire Mentors’ primary job is to teach students to master them. A few powers are forbidden, especially Pyrokinesis, the ability to start fires.

Fire is a major, recurring symbol in the story. Fitz locates Sophie in San Diego, where fires ring the city. Similar fires break out near cities around the world. They’re caused by renegade groups that protest the Council’s unwillingness to deal with the rising dangers presented by human technology. The fires also might be an early salvo in one group’s attempt to kill off all humans.

Grady and Edaline’s daughter, Jolie, dies in a house fire. Sophie suffers a recurrent nightmare where her human parents are trapped in a burning house. She’s terrible at fire-catching, a skill required to pass elementalism class. She sets fire to a pile of leaves to help a flareadon stay warm, which upsets Edaline.