The publication of this series was met with immediate success because readers quickly became enamored with the characters and the adventure. The story of Amy and Dan Cahill unfolds throughout the 39 Clues books in order.
It begins as the young siblings are the heirs to their grandmother’s estate and must answer a question: Do they want one million dollars or a clue? What ensues are epic adventures around the world as Amy and Dan must contend with foes, betrayals, and shocking revelations.
About 39 Clues Books
The 39 Clues books are unique in that nearly every book is by a different author. The authors for the original series alone include Rick Riordan, Gordon Korman, Peter Lerangis, Jude Watson, Patrick Carman, Linda Sue Park, and Margaret Peterson Haddix.
Game cards were also included with the books which allowed readers to play an online version of Amy and Dan’s hunt, making this series a truly interactive experience for readers. This undeniably contributed to the success of the series.
Before the tenth book in the original series had hit bookstore shelves, the series had already sold 8.5 million copies around the world. Following that tenth book there would be one more book in the original series. This eleventh book would be the transition for the spin-offs. Then there would be five spin-off series and two companion books.
There have also been talks about a movie adaptation since 2008 as well. The movie rights were first acquired by DreamWorks and Steven Spielberg was rumored to be at the helm. During that development process, Shawn Levy wrote a script.
However, nothing came to fruition. Then, in 2013 it was announced that negotiations were taking place for Universal to acquire the rights. Since the latest announcement surrounding this adaptation was about a decade ago, it seems unlikely that Amy and Dan Cahill will be hitting screens any time soon.
The 39 Clues Books in Order
Original 39 Clues Series
While there are more than 40 39 Clues books in total, you should absolutely begin with the original series. The below books explain the framework of the world as well as the protagonists Amy and Dan Cahill. The spin-off books following the completion of this series were all written with the presumption that the original series had already been read, so this will ensure the best reading experience.
Furthermore, you should read these books in order of publication which matches the chronological order.
- The Maze of Bones (2008)
- One False Note (2008)
- The Sword Thief (2009)
- Beyond the Grave (2009)
- The Black Circle (2009)
- In Too Deep (2009)
- The Viper’s Nest (2010)
- The Emperor’s Code (2010)
- Storm Warning (2010)
- Into the Gauntlet (2010)
- Vespers Rising (2011)
Other 39 Clues Books
There are also companion 39 Clues books that are perfect for any superfan of the series.
- The 39 Clues: Agent Handbook (2010)
- The Black Book of Buried Secrets (2012)
Cahills vs. Vespers Books
The history between the Cahills and the Vespers is fraught and one that began to be revealed in the original 39 Clues books. But this spin-off dives even deeper into the animosity between these two clans. That’s because Cahills around the world are being kidnapped and the Cahill siblings must fulfill a bizarre ransom to save them.
- The Medusa Plot (2011)
- A King’s Ransom (2011)
- The Dead of Night (2012)
- Shatterproof (2012)
- Trust No One (2012)
- Day of Doom (2013)
Rapid Fire Books
As the series title suggests, these are rapid fire short stories that culminate in a reveal. The first story begins with Grace Cahill as she makes the fateful decision to ask her grandchildren a question that will change the world.
- Legacy (2011)
- Ignition (2011)
- Hunted (2011)
- Crushed (2011)
- Turbulence (2011)
- Invasion (2011)
- Fireworks (2011)
The Cahill Files Books
This spin-off series jumps throughout history to reveal different members of the Cahill family and what they have done to protect the Clues. These books take place from the 1600s into the 20th century and feature familiar Cahill faces as well as brand-new family members. Then the final book, Spymasters, is a compilation of the second, third, and fourth titles.
- Operation Trinity (2012)
- The Submarine Job (2012)
- The Redcoat Chase (2012)
- The Houdini Escape (2012)
- Silent Night (2012)
- Spymasters (2013)
Unstoppable Books
The fourth spin-off of the original 39 Clues books in order are the Unstoppable books. The 39 Clues have fallen into the wrong hands many years after the original series. So now the Cahills must find the serum antidote and stop their enemy from using the serum to gain control over the entire world.
- Nowhere to Run (2013)
- Breakaway (2013)
- Countdown (2014)
- Flashpoint (2014)
Doublecross Books
Finally, the last spin-off from the original 39 Clues series is Doublecross. The first book introduces the Outcast. He was banished from the Cahill family many years ago and never mentioned again, but he has been lurking and biding his time. He has been waiting for his revenge.
The first four books follow four of history’s most infamous disasters, which the Outcast recreates and the Cahill children must stop. Then the fifth book features the return of a traitor that Dan must track down.
- Mission Titanic (2015)
- Mission Hindenburg (2015)
- Mission Hurricane (2016)
- Mission Atomic (2016)
- Outbreak (2016)
A Summary of 39 Clues Books in Order
Below you will find the summaries of the original 39 Clues books in order. If you haven’t read these books, there will be minor spoilers as the series progresses. However, these summaries will help explain the scope of the adventures in this series.
1. The Maze of Bones
In her will, the Cahill matriarch left her descendants a choice: One million dollars or a clue. Grace was the head of the world’s most powerful family with relations to Marie Curie and Harry Houdini.
There are 39 Clues around the world that Amy and Dan must uncover if they wish to learn their family’s secret. However, as the search begins, the siblings must decide whether the clues are more important than finding out what really happened to their parents.
2. One False Note
Amy and Dan are not the only ones searching for the 39 Clues, but they are in the lead and on the way to Vienna. They have a piece of Mozart’s sheet music, but it is in code and seems to be the key to finding the next Clue.
However, other members of the Cahill family in search of the familial power are hot on their tail. Now Amy and Dan can’t tell if they’re heading toward victory or into a deadly trap.
3. The Sword Thief
Amy and Dan have been found again, but this time in the company of Alistair Oh, who is notoriously unreliable. Surely they wouldn’t have been foolish enough to forge an alliance with him?
Spies are reporting that the siblings are tracking down one of the most powerful fighters in the world. But if their warrior was a Cahill, he would be well-guarded and the price to uncover his secrets might just be lethal.
4. Beyond the Grave
Fourteen-year-old Amy Cahill and her younger brother Dan have been betrayed by their cousins and abandoned by their uncle. They have only the faintest hint to guide them as they rush to Egypt in search of the next clue in their search for the Cahill power.
But when they arrive, they find a message from their deceased grandmother, Grace. Did she leave this message to help them, or are they about to undergo the most devastating betrayal possible?
5. The Black Circle
Amy and Dan Cahill receive a strange telegram that lures them deep into Russia and far from the only adult they trust. It bears the initials NRR and launches a race to discover treasure stolen by Nazis and the truth behind the murder of the last Russian royal family.
But very quickly the treasure hunt begins to look like a Lucian trap. The bait might be irresistible with the temptation for Amy and Dan to find out what really happened on the night their parents died.
6. In Too Deep
Amy and Dan are in pursuit of secrets their grandmother would never have wanted them to know. That’s because they’ve uncovered a hint from their parents’ past.
But just as their enemies get close, awful memories begin to overwhelm Amy. How far will she go to protect Dan and how much of a Cahill is she prepared to be?
7. The Viper’s Nest
The hunt for the 39 Clues to recover unimaginable power has taken an incredibly heavy toll on Amy and Dan Cahill.
They just watched a woman die. The Indonesian police are tracking them down. They are also stuck on an island with a man who knows far too much about the death of their parents. And now a storm is rolling in.
Then, just when they think it can’t get any worse, it does. That’s because there is one more skeleton rattling in the Cahill closet and its discovery will reveal a terrible truth about their family branch.
8. The Emperor’s Code
The race for the 39 Clues is building to an explosive finish, but first they must steal another Clue. Except this one is under the protection of thousands of the world’s best soldiers amidst an ancient culture. It is the most dangerous Clue search yet.
As their enemies creep closer, Amy and Dan will also be separated for the first time ever. They must decide whether to find the next clue or find their way back to one another.
9. Storm Warning
Amy and Dan Cahill have faced some of the darker aspects of history in their search for the 39 Clues. They’ve also had to accept the role their family played, but are they ready for the whole truth?
They will embark on the high seas as they follow the trail of their infamous ancestors to discover a long-lost treasure. But the real prize won’t be hidden in a chest. It will be the discovery of the Madrigals’ most dangerous secret and the true identity of the mysterious man in black.
10. Into the Gauntlet
Not only are Amy and Dan Cahill expected to find all 39 Clues first, but they’re also expected to reunite their backstabbing family. The family who killed their parents. They’ve had enough.
But they also haven’t survived explosions and assassination attempts for nothing. Amy and Dan have a plan to find the remaining clues on their own terms. Except the Madrigals are still hiding one final, fatal secret that could cost everything.
11. Vespers Rising
The Cahills thought they were the most powerful family in the world. They also thought they were the only ones who knew about Gideon Cahill and his Clues. But they were wrong.
The Vespers are powerful enemies who have been waiting in the shadows. They have bided their time, but now they are rising and the world will never be the same again.
Final thoughts
It is best to read the 39 Clues books in order so as to fully appreciate the adventures of Amy and Dan Cahill. These books quickly became bestsellers following their publication, and have remained a fan favorite among readers for the compelling plot twists and storyline.