The 39 Clues Series

Book review by
Matt Berman, Common Sense Media
The 39 Clues Series Book Poster Image
Parents recommendPopular with kids
Exciting mystery, heavily merchandised.

Parents say

age 9+
Based on 11 reviews

Kids say

age 9+
Based on 53 reviews

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A lot or a little?

The parents' guide to what's in this book.

Educational Value

Plenty of accurate information is thrown in about major historical figures (Ben Franklin and Mozart for starters) and destinations around the globe.

Positive Messages

Cheating, stealing, breaking and entering, are all OK and almost a sport in this contest. The main characters also learn again and again not to trust anyone as one character after another double crosses them. Although this book may give kids the travel bug and pique their curiosity for more info on historical figures.

Positive Role Models & Representations

Our heroes are virtuous and kind, though not always honest, and pretty much everyone else is nasty and downright evil. Even the people who start out seeming nice -- old friends of Grace Cahill, especially -- have a negative agenda.


Arson, explosions, and traps, all designed to kill, or at least sideline, the child heroes. Several fights, and people are injured.


A kiss between teens in book 3, and 20something Nellie falls for an archaeologist in book 4.


Plenty of mild name-calling between brother and sister.


But it's not just a story. Embedded within the series are incentives to buy more cards, register on a 39 Clues Web site, and enter a contest with cash prizes. There has even been a viral marketing campaign involving MySpace and YouTube. Nothing harmful, and books have certainly had associated merchandise before. But this one is just a little more bald-faced than most. Also, many products are mentioned, including electronics, candy (one character has his own Pez dispenser), soft drinks, ice cream, and cars.

Drinking, Drugs & Smoking

Adults drink champagne on a cruise. Amy and Dan find a secret recipe for a liqueur. Some of the characters use poison.

What parents need to know

Parents need to know that nearly everyone in the first book is trying to kill, sideline, or deceive the heroes, who are orphaned children. There is some violence (arson, explosions, traps, and several fights with injuries) though it's mostly cartoonish. This book includes incentives to purchase cards, register on a website, and sign up for a contest with cash prizes. It's also a popular mobile app with buzz that it's being made into a movie with Steven Spielberg attached.

User Reviews

  • Parents say
  • Kids say
Parent of a 6, 9, and 13-year-old Written bylsworsham November 14, 2008

Great despite the shameless merchandising

My 9 yo son really enjoyed this book, and together we really enjoy playing on the website.

I do agree that all the marketing/merchandising surrounding this ser... Continue reading
Adult Written byCharles R. September 13, 2017
Whilst I don't like the merchandising involved in this, it does not in any way interfere with the enjoyment of the series. At first, I got all the books fr... Continue reading
Teen, 13 years old Written byb0bthesheep123 March 2, 2010

Great for kids with a sense of mystery

This is one of the best books I gave ever read, and I have read a lot of books. My friends and i sit on he bus discussing clues, looking at the trading cards th... Continue reading
Kid, 11 years old January 28, 2012


it is pretty good even though i havent read it yet!

What's the story?

Orphans Amy and Dan belong to a rich and powerful family related to nearly everyone important in history. When their grandmother dies, she leaves 39 clues, spread across the planet, to a treasure that will make the finder immensely powerful. So all the relatives, none of them decent or honest (except Amy and Dan, of course), compete to find and solve the clues while trying to eliminate their competition. This proposed 10-book series (10 physical books followed by 29 online-only installments), each by a different author, includes cards plus a code for a Web site with an online game with cash prizes.

Is it any good?

Taken simply as a story, this first book is pretty good. Sure, you have to park your disbelief at the door and give up on any expectation of realism. That done, it's loads of fun, with action, mysteries, and clues. It's clearly intended to make money, and a little more baldly than most. But as long as the writing is good and the story is fun, who cares? And Rick Riordan, author of the Percy Jackson series, knows how to pace a story.

The second installment keeps moving like the first -- from Vienna to Salzburg to Venice this time. And it keeps you guessing about how the clues will fit together. But the brother-sister team seems less likable here. Dan won't stop whining about how boring he thinks Mozart is and the two won't stock bickering. It overshadows their talents and makes you wonder how they're able to stay ahead of the competition.

The third installment sends the Cahills to Japan and Korea and teams up Amy and Dan with ruthless relatives Ian and Natalie Kabra. The book starts and ends with fun flourishes and twists but it also gets to the heart of what the four Cahill branches are really fighting over -- and it's not all that original. Also, the puzzles leading to the clues are confusing and the romantic subplot feels clumsily put together.

Dan and Amy Cahill work their way through Egypt in the fourth installment. Lucky for them their grandma has left numerous hints around Cairo and the tombs. Once again this installment doesn't hold a candle to the first in the series. There's no logical flow from one clue to the next and the way the kids figure out some of the puzzles makes no sense. It's too bad because Egypt is such an exciting place for a treasure hunt.

Talk to your kids about ...

  • Families can talk about marketing. Why does the book include playing cards? Why is there a Web site and contest, with cash prizes? What do the publishers have to gain by giving away money?

  • What do they mean when they call this a "multi-platform series"?

Book details

Our editors recommend

For kids who love adventure stories

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