Into the Gauntlet  Into the Gauntlet is the tenth book in "The 39 Clues" novel series. It was written by Margaret Peterson Haddix and released on August 31, 2010. In the beginning of the book, Amy and Dan are now at the end of their clue hunt, and every misfortune they've had. Their lead is a poem found in their hotel room. However, it is then stolen by Isabel Kabra. It is revealed that William Shakespeare was a powerful Madrigal and the most important clue is on the line against their competitors. Dan and Amy are supposed to go to the Globe theater to watch a Shakespeare play, "Romeo and Julliet". While watching the show they see what looks to be ninjas. The ninjas find a clue at the top of the theater but drop it into the hands of Dan and Amy. As it turns out the whole Cahill family is at the play looking for the clue. Backstage of the play the fight over the paper found at the theater. McIntyre and Fiske Cahill reveal there is another family out there that makes Isabel Kabra look like Mother Teresa. The globe on the 39 Clues symbol is, unlike in the first nine books, shattered into pieces. The message on the cards is, "Only together can we fight the true enemy." The secret message in the book is "The Cahills aren't the only ones looking for the Clues. The Vespers are coming." "Into the Gauntlet" begins as Amy and Dan Cahill enter a London hotel tired and with no lead whatsoever. They receive another lead, but this is stolen by Isabel Kabra via a pet monkey, who leaves them a coin with a fancy script K on it. However, Dan, who has already memorized it, rewrites it. Amy looks all over the Internet to find out what it means, and she is about to shout out when Nellie realizes that the Kabra coin is a bug. She destroys it, along with three other bugs from each of the other three branches. Amy then tells them that the clue leads to William Shakespeare, so they go to a performance of Romeo and Juliet in The Globe Theatre. Once there, they confront the Starlings, who are back in the clue hunt after being sent to the hospital in an explosion back in "The Maze of Bones", and steal their lead, but they are trapped by Jonah Wizard, who was forced back into the clue hunt by Cora Wizard, the Holts, Alistair Oh, and the Kabras.