Published by Scholastic in 2008, Rick Riordan’s The Maze of Bones is the first novel in an interactive middle grade mystery-adventure series called The 39 Clues that follows the hidden exploits and conflicts of the Cahills, the most influential family in history. Riordan is a former teacher and prolific author best known for publishing the Percy Jackson series. The 39 Clues franchise proved to be another success, with books from the series landing on the New York Times for 48 weeks among other bestseller lists. Many notable children’s book authors contributed to the series, including Gordan Korman, Linda Sue Park, Peter Larangis, and Jude Watson. The series was optioned by Steven Spielberg but, as of 2024, has yet to be adapted for film or television.

The Maze of Bones chronicles the adventures of siblings Amy and Dan, who learn from their recently deceased grandmother’s will that they are members of the highly influential Cahill family and must embark on a dangerous, globetrotting clue hunt in search of a powerful treasure.

This guide is based on the 2008 Scholastic paper-over-board edition.

Content Warning: Some of the characters embody stereotypes. Jonah, one of few Black characters in the novel, is shown wearing heavy jewelry and using words like “gangsta,” embodying known Black stereotypes. Irina Spasky’s name sounds like the word “spastic,” a word considered offensive by disability advocates. Irina is described as having a twitch in her eye, causing some family members to mock her and call her “Blinky.” Her portrayal can be read as embodying offensive stereotypes of people with physical disabilities affecting muscle coordination.

Plot Summary

Grace Cahill, the matriarch of the influential Cahill family, passes away, leaving a mysterious challenge in her will. At her funeral, her orphaned grandchildren, bookish Amy (14) and energetic Dan (11) discover that they, along with other Cahill relatives belonging to four branches of the family, have the opportunity to unlock the 39 Clues. These are a series of hidden secrets that could lead to unimaginable power. Unbeknownst to Amy, Dan, or any other Cahills, Grace’s estate lawyer, William McIntyre, consults a man in a dark suit about a mysterious plan they intend to keep from the family members.

Grace’s will presents Amy and Dan with a choice: Take $1 million or embark on a quest to uncover the 39 Clues. To make Grace and their parents proud, Amy and Dan choose to take the challenge, setting off on a dangerous adventure that will take them across the globe. So too do the rich Kabra siblings, the militant Holt family, the preppy Starling siblings, the famous Jonah Wizard, the cunning Alistair Oh, and the trained KGB spy, Irina Spasky.

The first clue leads Amy and Dan to inventor, writer, and Founding Father Benjamin Franklin. They discover a copy of Franklin’s Poor Richard’s Almanac, encouraging them to follow Franklin’s travels and look for a “maze of bones” (53). A massive housefire erupts in Grace’s mansion, and the siblings narrowly escape but lose the clue to Alistair Oh. They notice a mysterious man in a dark suit watching them.

Dan and Amy enlist the help of their au pair, Nellie, to help them navigate their next destination: Philadelphia. Dodging attacks from their relatives, Amy and Dan uncover secret messages in Franklin’s papers and learn that he too was a Cahill, joining the ranks of other influential figures from history. Amy and Dan’s new clue nearly gets stolen by the Starlings, but a bomb explodes in the museum, incapacitating them.

Amy and Dan follow Franklin’s life story to Paris to uncover the next clue. They trail Irina Spasky through a clubhouse operated by the Lucian branch of the family and discover coordinates of interest. They follow the map to a cemetery only to discover that they’ve walked into a trap: The ground falls away and they land in a pit. The Holts try to steal their clue but get intercepted by mysterious attackers. Dan throws a concussive grenade at the Holts, and the siblings escape, spotting the man in the dark suit watching from the shadows.

The next clue leads Amy and Dan to the Catacombs, tunnels under Paris lined with human remains. They solve a number riddle to uncover coordinates to the next clue. When the Kabras ambush them, the siblings flee into a train tunnel, where an oncoming train destroys the last photo Dan has of his parents. Amy comforts Dan as he confronts his true feelings about losing his parents and his grandmother.

Amy and Dan consult Franklin’s papers at the library, discovering his interest in iron solute and finding a map created by scientists who used Franklin’s lightning rod technology. Amy and Dan follow the coordinates to a churchyard and find another entrance to the Catacombs. Inside the chamber, they discover a mural depicting the four original Cahill siblings fighting. They also find a vase with sheet music inscribed on the base and a paper-wrapped vial inside. They realize they need to charge the contents of the vial just as Jonah Wizard arrives to steal the clue. Amy finds her voice and stands up for herself and Dan. Amy and Dan fight their way past other relatives to get to the roof, where Amy uses Franklin’s lightning rod to charge the vial. The Kabras swoop in and steal the charged vial, but Amy and Dan get away with the real clue, the sheet music printed on the wrapping. They realize the first clue led to “iron solute,” an ingredient. The second clue points to Vienna, the home of Wolfgang Amadeus Mozart.

As the siblings leave, McIntyre meets with the man in the dark suit again and vows to watch Amy and Dan more closely.