This was one tumultuous ride! I loved the beginning, with Albert Einstein's death and the immediate descent of agents on his house, and the clues from books he owned. Including famous historical figures into more modern stories is a great way to get children interested in biographies, and Einstein was a great choice. The fact that Charlie doesn't have to worry about parents or money will appeal to young readers, and the travel to different places appealed to me! This really doesn't slow down for a minute, in the best possible way.
Gibbs is hugely popular with my students, who love his Funjungle, Spy School and Space Base Alpha mysteries. There were practically fist fights over my one copy of this book!