Into the Gauntlet (The 39 Clues Series #10) by Margaret Peterson Haddix

Into the Gauntlet by Margaret Peterson Haddix is the final book in the 39 Clues Series. In this novel, Amy and Dan find themselves following leads to Shakespeare's final resting place. All of the other family members are hot on their trail and have actually resorted to following them to find the clues! It turns out that all of the 5 family branches (Tomas, Janus, Ekaterina, Lucian, and Madrigal, named after the 5 children of Olivia and Gideon Cahill) have 38 of the clues between them - if they would just get along and share, they could easily solve the entire mystery together. Unfortunately, the majority of the Cahills are cut-throat, greedy, and uninterested in "bonding". Amy and Dan have been asked to do just that - reunite the descendants of Gideon and Olivia Cahill. They are convinced that finding the last clue will give them enough power to convince the other teams to unite, but they'll have to survive The Gauntlet and their competition first!

This was an AWESOME ending to the series! Like the other books in the series, it was filled with action, adventure, mystery, and some interesting historical facts. I absolutely loved the way the story came together and I'm really happy with the end. I am really excited to read the new series about another family who has also been after the Cahill Clues. The first book, Vespers Rising comes out in April, 2011.