I couldn't put it down.
Great and interesting read
It was so good I want the next book in the series!!!!!!!!!!!!
I liked this book because it had a lot of action and mysteries to solve. Charlie reunites with her brother and they must solve a case that Einstein designed so that only a high IQ person could figure it out. Even though Charlie was only 12 years old she was able to be helpful and useful and proved to be a good person in her brother's eyes.
THIS was a amazing book that I read 30-40 times, you'll love it if you like action, and a little comedy. I've said it before; I'll say it again: BEST BOOK EVER!!!!!!!