HootRated mascot HootRated

Underground Ghosts

Dori Hillestad Butler

Cover of Underground Ghosts

Underground Ghosts

Age Rating, Reading Level & Content Guide

A Super Special

by Dori Hillestad Butler

Reading Level 4-5 9LE Ages 9-12 Balanced Read

The text is written at a 4th grade reading level, the subject matter is intended for middle graders (ages 9–12), and the content is mild with minimal sensitive material.

We may earn a commission from these links. Bookshop.org supports independent bookstores with every purchase.

About This Book

The musty scent of old books mixes with the cool dampness of underground tunnels as whispers echo through the shadows. Kaz and Claire can almost feel the chill of a ghostly presence in the Seattle library’s hidden passages. What secrets lie beneath the city, and can they help a lost spirit find its way home?

Themes

FriendshipAdventureMysteryHalloweenLibraries

Quick Assessment

This final installment in Dori Hillestad Butler's Haunted Library series blends mystery with light supernatural elements suitable for middle-grade readers aged 9 to 12. Set around Halloween in Seattle, the story focuses on friendship, problem-solving, and exploration without intense scares. Parents can expect an engaging, age-appropriate mystery that encourages curiosity and empathy.

Why we rated Underground Ghosts 9LE

Underground Ghosts is written at a Level 4-5 reading level across 192 pages. Strong independent readers around grade 5.5 can typically handle this book on their own; with parent or teacher support, Underground Ghosts works for readers up to grade 6.5.

We rate Underground Ghosts as 9LE ("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, Underground Ghosts explores friendship, adventure, mystery, halloween, and libraries — 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.
  • Kids drawn to stories about friendship, adventure, mystery.

Maybe not for

  • ! Readers looking for something heavier — this is a gentle, low-stakes story by design.

For Parents

Content Intensity

9LE — Light — Emotional
Emotional
Light
Physical
Clear
Social
Clear
Thematic
Clear

Light conflict or tension. Mild peril resolved quickly.

Data confidence: standard

Was our "Mild" content intensity rating accurate for this book?

Reading Insights

Hook Factor

3/10

A steady, thoughtful read that rewards patient readers.

Discussion Potential

1/10

A lighter read — great for independent enjoyment.

Book DNA

Multi-dimensional content fingerprint

Vocabulary Level
4
Emotional Weight
4
Theme Richness
5
World Scope
1
Data Confidence
7

Similar Books

Based on content and theme analysis

See all books like this →

Details

Book Length

192 pages
ISBN
9780515157116
Pages
192
Publisher
Penguin Publishing Group
Published
2017
Type
Fiction

Subjects

LibrariesFriendshipHalloweenSeattle