Line of Fire
Franklin W. Dixon
Line of Fire
Age Rating, Reading Level & Content Guide
The Hardy Boys Casefiles #16
by Franklin W. Dixon
The text is written at a 4th grade reading level, the subject matter is intended for middle graders (ages 9–12), and the content has moderate intensity with some emotionally heavy themes.
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About This Book
Smoke curls thick and sharp as Frank and Joe race through the blazing chemical plant, searching for clues that could prove Denny’s father was no accident. Flames crackle around them while secrets hide in every shadow. Just when they think they’re close to the truth, a sudden explosion stops them in their tracks.
Quick Assessment
This middle-grade mystery follows Frank and Joe Hardy as they help their friend Denny uncover the truth behind a suspicious fire at a chemical plant that may have been a cover-up for foul play. The story contains themes of espionage and detective work appropriate for ages 9 to 12, with moderate suspense and some perilous situations. Parents should be aware of scenes involving fire and danger but will find the content suitable for young readers interested in mysteries.
Why we rated Line of Fire 9MP
Line of Fire is written at a Level 4-5 reading level across 160 pages. Strong independent readers around grade 5.5 can typically handle this book on their own; with parent or teacher support, Line of Fire works for readers up to grade 6.5.
We rate Line of Fire as 9MP ("Moderate — Physical") because the content sits in the "Moderate" range — moderate conflict that may involve loss, scary scenes, or interpersonal stakes. The strongest signals come from physical peril — these are the dimensions parents should evaluate against their reader's tolerance.
No specific content flags were raised by community reviewers, which is consistent with the moderate intensity score.
Thematically, Line of Fire explores mystery, adventure, and friendship — 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 mystery, adventure, friendship.
Maybe not for
- ! Readers who get easily upset by emotional or moderately dark scenes — the conflict here is real, not just background flavor.
For Parents
Content Intensity
9MP — Moderate — PhysicalReal stakes and emotional weight. May include sustained danger, loss, or bullying.
Was our "Moderate" content intensity rating accurate for this book?
Reading Insights
Hook Factor
3/10A steady, thoughtful read that rewards patient readers.
Discussion Potential
2/10A lighter read — great for independent enjoyment.
Book DNA
Multi-dimensional content fingerprint
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Details
Book Length
- ISBN
- 9780671688059
- Pages
- 160
- Publisher
- Pocket Books
- Published
- May 15, 1989
- Type
- Fiction