The 39 Clues Wiki
The 39 Clues Wiki

One False Note is the second book in the 39 Clues series. It was written by Gordon Korman. It was released on December 3, 2008.

Like most books in The 39 Clues series, One False Note revolves around a historical figure, Wolfgang Amadeus Mozart, a Janus.

Back Summary[]


The race is on to find 39 Clues that safeguard a great power, and fourteen-year-old Amy Cahill and her younger brother, Dan, are shocked to find themselves in the lead. The search seems to be taking them to Vienna, and they hold a coded piece of Mozart's sheet music that's key to finding the next Clue. But tailed by a pack of power-hungry relatives, Amy and Dan can't see if they are sailing toward victory-or straight into a deadly trap. How much will it take for Amy and Dan to become the young heroes and gain their family's secret power​?"

Plot Overview[]

Amy, Dan, and their Au pair, Nellie, found music by Wolfgang Amadeus Mozart in the end of The Maze of Bones, so they go to Vienna, Austria, to learn more about him. On the train, the Holts attack them to steal the music, but they fail when Saladin eats the sheet of music from Paris. Since Dan has a photographic memory, he rewrites the song music on a train napkin.


Mozart's music sheet

Wolfgang amadeus mozart child

Wolfgang Amadeus Mozart

In Vienna, Amy and Dan discover that Mozart had an older sister: Maria Anna "Nannerl" Mozart. They go to a library and ask for her diary but find out that Jonah Wizard stole it. They steal it from him in his hotel suite and Nellie accidentally goes into the wrong room dressed as a maid,, and is forced to clean the dukes' toilet. Once back at their hotel, they find out Nellie was arrested but after an encounter with Irina Spasky, They find Nellie was dismissed. Later, Nellie translates it and notices that three pages are missing.

Then, Amy and Dan discovers that there is another song in the middle of the song by Mozart. That song's name is "The Place Where I Born", so they go to the place where Mozart was born: Salzburg, Austria. There, they see Alistair Oh, and follow him. He goes into the Salzburg Catacombs, and they follow him in. There, Amy and Dan see The Man in Black, and there is an explosion, and they are forced to go deeper in. They eventually find an old paper, and they believe it is the recipe for the whole serum. Later in the car, Nellie reads it and they find it is the recipe known only to the benedictine brothers of the Salzburg Catacombs. They send it back to them and, discouraged, return to their hotel.

Later, Nellie discovers a homing device on the collar of their cat, Saladin. They place it in Alistair Oh's cane when he is sleeping. They also steal a document from him. It mentions Venice, Italy, so they go there.

In Venice, they follow Jonah Wizard, and find a secret passage in a music store called Disco Volante to a Janus stronghold. There, they find the missing diary pages, and steal them. The pages say that Nannerl Mozart thought her brother was going crazy because he was getting into debt by buying Japanese steel. A name, Fidelio Racco, which was also found on the paper taken from Alistair Oh, appears in the diary. Because of that, Amy and Dan go into Fidelio's Racco's mansion (which is now a museum). There they see the Kabras, who attack them, but Ian falls into the booby trapped key playing Mozart's song on the Harpsichord, and is knocked unconscious while Dan throws a tranquilizer dart at Natalie knocking her out.

Then, in the same place, Amy and Dan find the second Clue, tungsten, and two Japanese swords. Because of that, Amy, Dan, and Nellie buy plane tickets to Tokyo, Japan.

The book ends with Alistair Oh finding out who is owner of the tracking device that was placed on Saladin and himself. That person is Grace's lawyer and friend, William McIntyre.

In the audio book, there is an audio extra bout one of Grace Cahill's hearings.


Historical Cahills mentioned[]


Tungsten (a.k.a. Wolfram).

Secret Message[]

On the inside front cover, the middle shard has a piece of a music sheet. Excluding only the treble clef, the note names, along with the letters, spell "Gideon".

Also, on pages 83–95, each letter is placed one backward in the alphabet. When decoded, the message reads "Look to India."



To: Agents with Top Secret Security Clearance

Re: The Cahill Family

ATTENTION: Our spies across the globe report new activity in the Cahill family. Rumors are coming thick and fast. But the best intelligence we have suggests the Grace Cahill (internal code-name: Wildcat) has launched a hunt for some sort of "Clues" hidden around the world. Cahills who find "Clues" are eligible to win $100,000 in prizes.

OUR MISSION: To try to infiltrate the notorious Cahill family and find the hidden "Clues" - whatever they may be.

OUR METHOD: To impersonate actual Cahill family members.

Good luck. You're going to need it.

P.S. Make sure Klose doesn't see this!

Cover Art[]

The second book has a green cover. Not noticed by most, the cover of each of the first three books are designed to foreshadow the next book: on the first book, you see shards of the glass that is on the front of the second book; the second book shows skulls on the left, the glass in the center, and a sword in the right; and in the third book, it shows glass at the left and nothing on the right. By the fourth book, the pattern was dropped in favor of more appealing covers.

Also, one of the glass shards has Maria Anna "Nannerl" Mozart's face on them.

Card Combo[]

Card17 Card18 Card19 Rifatcard20 Rifatcard21 Rifatcard22 Clue28