100 Scope Notes
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Endangered Series #20: The 39 Clues

Popularity comes, popularity goes. As librarians we’re always balancing between what will circulate like crazy and what we need to have in the collection. And we’re not the Library of Congress – we can’t (and shouldn’t) keep everything.

An endangered series is one that appears to be waning in terms of popularity. But popularity isn’t everything. Should it stay, or should it go? Or think of it this way – if you were starting a library today, would this series make the cut? Let’s discuss.

The 39 Clues (Series) by various authors

This adventure series began in 2008 with Maze of Bones and continued (through various spin-off series) until 2016. A lot of well-known authors wrote books in the series. It made a big splash, with interactive online elements for readers to explore.

The Case for Keeping: The series isn’t all that old yet (or am I being too generous?). It still feels fairly modern and the adventure/mystery genre is always a page-turner. A big-screen adaptation could potentially give a boost. Steven Spielberg acquired the film rights in 2008, but the movie has yet to make it to the production stage (so we probably shouldn’t hold our breath on that).

The Case for Not: I don’t know about your library, but the interest in these books at my school has really dipped. They are paper over board books, and our collection is looking a little ragged at this point.

Refresh? Since this is a relatively new series, there are no new covers or reboots.

My Verdict: We are weeding the damaged copies and not replacing, unless a booktalk next year can get them going again.

What are you doing with this series at your library?


Endangered Series #1: The Boxcar Children

Endangered Series #2: The Hardy Boys

Endangered Series #3: American Girl

Endangered Series #4: The Baby Sitter’s Club

Endangered Series #5: The Bailey School Kids

Endangered Series #6: Nate the Great

Endangered Series #7: Cam Jansen

Endangered Series #8: The Kids of the Polk Street School

Endangered Series #9: Pony Pals

Endangered Series #10: Little Bill

Endagered Series #11: Animal Ark

Endangered Series #12: Arthur

Endangered Series #13: The English Roses

Endangered Series #14: Marvin Redpost

Endangered Series #15: Little Critter

Endangered Series #16: Spiderwick Chronicles

Endangered Series #17: Junie B. Jones

Endangered Series #18: Magic School Bus

Endangered Series #19: Dear America

About Travis Jonker

Travis Jonker is an elementary school librarian in Michigan. He writes reviews (and the occasional article or two) for School Library Journal and is a member of the 2014 Caldecott committee. You can email Travis at scopenotes@gmail.com, or follow him on Twitter: @100scopenotes.


  1. My copies sat on the shelf, unloved for a long time, but we had a guest teacher this year who read them as a read-aloud while our kids were having lunch. Now I can’t keep them on the shelf!

  2. Jennifer Nelson says

    Here are a couple I’m struggling with right now:
    Puppy Place
    Time Warp Trio

    I’d especially love some advice on better options than our extensive collection of Great Illustrated Classics! :-)

    I love these posts, so thank you for continuing them!

    • Travis Jonker says

      Thanks for mentioning these! Puppy Place is still doing well in my K-3 library. Not so much for TWT.