Details: This beaded bookmark with a tassel shows Aym and Andy. At the top it says 'The 39 Clues' and at the bottom it says 'Every family has its secrets'.
The 39 Clues is a series of adventure books, combining reading, online gaming, and card collecting. Published by Scholastic, the main part of the series consists of ten books about the adventures of siblings Amy and Dan Cahill trying to thwart the other Cahills to get the Clues. Continuing books will be about the rising of a new family, the Vespers. They agree to the challenge in their grandmother Grace Cahill's will and search for 39 Clues scattered around the world. Rick Riordan wrote the first book and the main story arc, however, other authors wrote the remainder of the books in the series. Due to the series' integration of online gaming and card collecting with reading, the series creates an interactive experience. In addition, there are exclusive prizes for children, winnable by buying the books and playing the online game. The novels are designed to incorporate historical elements by placing famous people in the midst of the Cahill family.