Blooper: The first printing for the first book gives Stina's family name as "Logner" before switching to "Heks" the next time its mentioned. The annotated version of the first book points out the mistake; according to Messenger, she'd gotten confused by her notes, thought she'd forgotten to give them a last name, and asked her editor to add it in. Future printings fixed the error.
Schedule Slip: The tenth novel was originally intended to be released sometime in the fall of 2023. This was pushed back and replaced with the first part of a graphic novel adaptation of the series' first entry. This is because Messenger became pregnant with her second child during the writing of Book 10, and wanted to prioritize her and her baby's health over meeting a deadline.
Tribute to Fido: The Fosters' cat, Marty, was based on one of the author's cats.
What Could Have Been: Foxfire was named "Hawksfire" for several drafts because the author wasn't sure if she should name the school after a fungus. She eventually decided that the elves would see beauty even in fungi.
Working Title: The first book was originally named Chasing Everblaze, then briefly just Everblaze, before settling on Keeper of the Lost Cities. The Everblaze name would ultimately be used for the third book.
Miscellaneous trivia
Foxfire's architecture is loosely inspired by the Louvre.
from throughout the series.