What reading level is Ruby Key (Moon & Sun)?

Ruby Key (Moon & Sun) by Holly Lisle is at a Level 5-6 reading level (Lexile 860L). Recommended for Middle Grades readers (Ages 9-12).

What age is Ruby Key (Moon & Sun) appropriate for?

Ruby Key (Moon & Sun) is recommended for Ages 9-12. HootRating: 10LE (Light — Emotional).

What genre is Ruby Key (Moon & Sun)?

Ruby Key (Moon & Sun) is fiction — Juvenile Fiction.

Does Ruby Key (Moon & Sun) have any content warnings?

Ruby Key (Moon & Sun) has a HootRating of 10LE (Light — Emotional). No specific content flags noted. On HootRated, every book is rated across four dimensions — emotional, physical, social, and thematic — to help parents make informed choices.

How many pages is Ruby Key (Moon & Sun)?

Ruby Key (Moon & Sun) by Holly Lisle is 368 pages.

Reviewed by HootRated editorial · Last updated September 7, 2026

Ruby Key (Moon & Sun)

Holly Lisle

Ruby Key (Moon & Sun)

Age Rating, Reading Level & Content Guide

by Holly Lisle

Reading Level 5-6 10LE Ages 9-12 Balanced Read

The text is written at a 5th grade reading level, the subject matter is intended for middle graders (ages 9–12), and the content is mild with minimal sensitive material.

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About This Book

What if the world you know hides a secret so big it could change everything? Imagine sneaking into the old forest under the moonlight and discovering a Nightling slave with a secret that could shake both your worlds. Can Genna and Dan keep this secret safe, or will danger follow them home?

Themes

Adventure Fantasy World-Building Friendship Family

Quick Assessment

Ruby Key is a middle-grade fantasy adventure that explores themes of friendship and courage as siblings Genna and Dan uncover a hidden world of Nightlings. Suitable for ages 9-12, it includes mild peril and fantasy violence appropriate for this age group. The story encourages imagination and empathy while delivering an exciting, fast-paced narrative.

Why we rated Ruby Key (Moon & Sun) 10LE

Ruby Key (Moon & Sun) is written at a Level 5-6 reading level with a Lexile measure of 860L across 368 pages. Strong independent readers around grade 6.5 can typically handle this book on their own; with parent or teacher support, Ruby Key (Moon & Sun) works for readers up to grade 7.5.

We rate Ruby Key (Moon & Sun) as 10LE ("Light — Emotional") because the content sits in the "Mild" range — mild conflict — the kind a child encounters in normal play and sibling life. Across our four dimensions (emotional, physical, social, thematic) the book reads as evenly mild; no single dimension stands out as a concern.

No specific content flags were raised by community reviewers, which is consistent with the mild intensity score.

Thematically, Ruby Key (Moon & Sun) explores adventure, fantasy world-building, friendship, and family — these threads give the book room to mean different things to different readers.

Good fit for

✓ Children in the Ages 9-12 range — the maturity and attention span match the story's pacing.
✓ Patient readers who enjoy slower, character-driven stories.
✓ Kids drawn to stories about adventure, fantasy world-building, friendship.