50 Fun Facts About The 39 Clues

At Grace Cahill's will reading in The Maze of Bones, what must each heir give up to receive the first clue?

A million dollars is what most of the relatives walk away with. Amy and Dan want the money too, until they decide Grace would have wanted them to take the clue.

Which Hollywood director bought the film rights to The 39 Clues in June 2008, before the first book was published?

Steven Spielberg bought the rights about three months before The Maze of Bones went on sale. Shawn Levy, director of the Night at the Museum films, was later attached to direct.

In The 39 Clues, what are the thirty-nine clues that the Cahill family's rival branches race to collect?

Serum ingredients are what the family fights over: together they make a formula said to turn whoever completes it into the most powerful person in the world.

Which American founding father left the trail that sends Amy and Dan Cahill to Paris in The Maze of Bones?

Benjamin Franklin is the first famous relative on the trail. In the story he hid a clue beneath Paris while serving there as an American diplomat.

Which au pair follows Amy and Dan Cahill around the world in The 39 Clues and turns out to be a pilot?

Nellie Gomez charges most of the flights and hotels to her own credit card to keep the hunt going. It later emerges that Grace herself had picked her for the job.

Which author, once a middle school teacher, wrote The Maze of Bones, the opening book of The 39 Clues?

Rick Riordan, best known for Percy Jackson, was asked by the publisher's editors to open the saga. The project was kept secret for about two years.

Which branch of the Cahill family do Amy and Dan learn they belong to at the end of The Viper's Nest?

Madrigal is the hidden fifth branch of the family. Dan works it out from Grace's journal, in which the letter M ties his parents to a Chinese leader.

Which underground Paris landmark hides the number puzzle that points Amy and Dan Cahill to Mozart?

The Catacombs are real: an underground ossuary created to relieve the overflowing cemeteries of Paris. Alistair Oh holds off two rivals there while Amy and Dan escape.

What is the name of Grace Cahill's Egyptian Mau cat, who travels with Amy and Dan in The 39 Clues?

Saladin shares his name with the sultan who led Muslim forces against the Crusaders. In the books the cat is very fond of red snapper.

In The 39 Clues, which convenience food is the Korean businessman Alistair Oh known for creating?

Microwavable burritos are his claim to fame, though bad investments later swallowed much of his money. He rarely travels without a diamond-tipped cane.

Which villain of The 39 Clues, a mother of two rival hunters, set the fire that killed Amy and Dan's parents?

Isabel Kabra is the main antagonist of the first ten books. Amy pieces the truth together from dreams and recollections on an Indonesian island in In Too Deep.

Who is unmasked in Storm Warning as the Man in Black who shadows Amy and Dan through The 39 Clues?

Fiske Cahill is Grace's younger brother, who vanished decades before the hunt, which is why Amy and Dan had never heard of him. He later becomes one of their legal guardians.

Which rival, at first a deadly enemy, dies saving Amy and Dan Cahill from a burning house in In Too Deep?

Irina Spasky, a former KGB agent, had grown fond of the children over the hunt. She had lost her own young son while she was away on a mission.

Which member of the Holt family rescues Amy Cahill when a villain dangles her over sharks in In Too Deep?

Hamilton steps in because of the alliance he struck with Amy and Dan in Russia one book earlier. The eldest Holt child is a football player and a master of parkour.

Which lawyer runs the reading of Grace Cahill's will that launches the hunt in The Maze of Bones?

William McIntyre switches the will to its alternate version at the dying Grace's request. He is also behind the tracking device hidden in the family cat's collar in One False Note.

In The 39 Clues, what is the rival clue hunter Jonah Wizard famous for around the world?

Hip-hop made him a teenage celebrity who also appears in action films, with his father Broderick as his manager. His mother, Cora, is a leader of the Janus branch.

Which talent of Dan Cahill's saves Mozart's sheet music after the Holts wreck it on a train in One False Note?

A photographic memory is Dan's great weapon in the hunt, along with a head for numbers and puzzles. He rewrites the whole piece on a napkin.

What breed of dog is Arnold, who goes along with the athletic Holt family on the hunt in The 39 Clues?

Pit bull Arnold travels with a family of Tomas athletes from Milwaukee, led by Eisenhower Holt, a security guard who was once expelled from West Point.

Which great-aunt is Amy and Dan Cahill's legal guardian when The 39 Clues begins?

Beatrice is Grace's sister. Once the children vanish on the hunt, she sends a private investigator after them.

Which ancestor, father of Luke, Katherine, Thomas and Jane, began the feuding family at the heart of The 39 Clues?

Gideon Cahill made his great discovery in 1507 while hunting for a cure for the plague. He died in a fire, and his children blamed one another and split apart.

In The Maze of Bones, the first clue is an anagram of which word from Grace Cahill's opening hint?

Resolution rearranges into iron solute, the first clue. Dan solves the anagram from the slip of paper that came with the vial, after a rival has stolen the vial itself.

In The Maze of Bones, what does Amy Cahill use at the top of a Paris church to charge the mysterious vial?

A lightning rod on the church gives the vial the electric charge it calls for. Amy and Dan climb the bell tower with the Holts chasing them.

What does a rival use to escape from a Paris bell tower with the charged vial in The Maze of Bones?

A kite carries Ian out of the tower like a glider moments after Amy has charged the vial. The liquid inside later turns out to be a Lucian poison.

At the end of The Maze of Bones, which city do Amy and Dan Cahill head for on the trail of Mozart?

Vienna is where the second book picks up. There the siblings learn that Mozart had a gifted sister whose diary has gone missing from a museum.

In One False Note, which sister of Mozart kept the diary that Amy and Dan take back from Jonah Wizard's hotel?

Nannerl, born Maria Anna, toured Europe as a child prodigy alongside her younger brother. In the novel, three pages of her diary turn out to be missing.

Which hard metal, forged into two swords hidden in a merchant's house, is the second clue in One False Note?

Tungsten is spelled out by a note Grace left: strike three letters from the French word for cake and the two that remain stand for the metal.

In One False Note, which booby-trapped instrument blows up when a rival plays Mozart's piece on it?

A harpsichord once owned by the merchant Fidelio Racco is rigged at a single key. Amy decodes the warning too late, then finishes the tune herself to open a hidden passage.

In One False Note, a record shop in which Italian city conceals the entrance to a Janus stronghold?

Venice gives the siblings a gondola chase across the canals after they steal the missing diary pages from the stronghold. Jane Cahill's branch first settled in the city.

Which Canadian author, first published at fourteen, wrote One False Note and The Emperor's Code for The 39 Clues?

Gordon Korman wrote his first novel as an assignment for a seventh-grade English class, then mailed the manuscript to a publisher himself. He went on to open the second 39 Clues story arc with The Medusa Plot.

At the end of One False Note, a pair of samurai swords points Amy and Dan Cahill towards which city?

Tokyo is where the swords came from. The siblings nearly miss the trip when two rivals pose as them at the airport and take their seats on the plane.

Which Japanese warlord who invaded Korea is the historical figure at the centre of the hunt in The Sword Thief?

Toyotomi Hideyoshi rose from a peasant family to complete the unification of Japan. In the story he is a son of Thomas Cahill, founder of the Tomas branch.

Which metal is revealed as the third clue when the hunters reach a warlord's hidden treasure in The Sword Thief?

Gold comes as no surprise to two of the rival teams, who had known it all along. The fragile alliance that found it falls apart moments later.

In The Sword Thief, which small object, handed to Amy Cahill by Ian, unlocks a hidden cave on a Korean mountain?

A coin taken from Ian's father serves as the key. Amy, charmed by Ian, hands it back once they are inside, and it is then used to lock her and Dan in the cave.

Which Egyptian queen, a wife of Ramesses the Great, has the tomb that Amy and Dan Cahill search in Beyond the Grave?

Nefertari has one of the largest and most lavish tombs in the Valley of the Queens. In the novel, drawings hidden inside goddess statues combine into a map of it.

Which fragrant resin, used by ancient Egyptians to embalm mummies, turns out to be the clue in Beyond the Grave?

Myrrh had been hinted at by Grace all along, as Amy finally realises. Along the way the siblings are marooned on a Nile island and chased by a crocodile.

In The Black Circle, the mysterious NRR says she is the daughter of which Romanov grand duchess?

Anastasia escaped her family's execution in the novel's version of events. Her daughter Nataliya, kept on the sidelines by haemophilia, guides Amy and Dan from inside a Lucian base.

Which lost Russian treasure, looted by the Nazis, are Amy and Dan Cahill led to in The Black Circle?

The Amber Room was once called an Eighth Wonder of the World, and its real trail goes cold in 1944. In the story it survives in secret and holds the fifth clue.

In In Too Deep, which famous pilot do Amy and Dan Cahill learn their parents were trailing across Australia?

Amelia Earhart, in the story, crossed paths with a scientist living in the outback under a false name. The siblings retrace their parents' journey with a pilot cousin of their father.

In In Too Deep, which volcano's eruption wrecked Robert Cahill Henderson's island laboratory in Indonesia?

Krakatoa erupted in 1883 with a blast heard thousands of kilometres away in Australia. In the story it wiped out the work of a scientist who had nearly assembled all 39 clues.

Which gemstone is mined at Coober Pedy, the outback town Amy and Dan Cahill visit in In Too Deep?

Opal is mined there in such quantity that the town is nicknamed the opal capital of the world. In the novel a villain drops venomous snakes and spiders on the hunters in the mines.

Which future British prime minister's time in South Africa do Amy and Dan Cahill investigate in The Viper's Nest?

Winston Churchill really did go to South Africa as a war reporter, and escaped from a prison camp in Pretoria. The novel has him there on the trail of the Zulu king Shaka.

In The Emperor's Code, which mountain do Amy and Dan Cahill fly up in an experimental helicopter?

Mount Everest hides a vial left, in the story, by the British climber George Mallory. Amy lets it fall in order to save a rival who is dangling from a cliff.

In The Emperor's Code, a poem written on which fabric, found in Beijing, turns out to be the clue itself?

Silk also carries a formula showing that four partial mixtures add up to one master version. Amy reveals the cloth just when Dan thinks the clue is lost for good.

Which pirate's name, inscribed in a locket, sends Amy and Dan Cahill to the Caribbean in Storm Warning?

Anne Bonny left behind a puzzle box in the story, and Amy and Dan are given one hour to open it in Jamaica. Dan had found her locket at a temple in China.

At which London theatre do the rival teams brawl over a scrap of paper at the start of Into the Gauntlet?

The Globe is staging Romeo and Juliet when the fight breaks out. The torn lead points on to Shakespeare's grave in Stratford-upon-Avon, which the hunters end up digging open.

Off the coast of which country is the Cahill family's ancestral island, where Into the Gauntlet ends?

Ireland is where the founder's house once stood. There the teams must work together through a gauntlet of doors, each opened by a question about the hunt.

Which publisher, the American home of Harry Potter, launched The 39 Clues as books tied to an online game?

Scholastic had its own editorial team come up with the idea before any author was hired. By mid-2010 the books had been translated into 24 languages.

Which shadowy organisation kidnaps seven Cahills in the second 39 Clues series, set two years after the clue hunt?

The Vespers descend from a nobleman who betrayed the family's founder five centuries earlier. They demand a ransom for the hostages, paid in objects the heroes must steal.

What came packed inside each book of the first 39 Clues series, printed with a code that unlocked a clue online?

Collectible cards came six to a book, and extra packs were sold separately. Readers typed the codes into an account on the official website to add clues to their collection.

Which bestselling writer of thrillers for adults wrote Day of Doom, the final book of the second 39 Clues series?

David Baldacci was a practising lawyer when he wrote his first novel, Absolute Power, which became a Clint Eastwood film. Day of Doom closes a six-book arc.