The best book. Didn't even have to read the cover to tell it was Stuart Gibbs. Great plot. Adventurous and suspenseful.

Great fast paced spy novel. With a female protagonist. A fun, interesting book full of plot twists and surprising mysteries and codes.

This is a great book. I love Stuart Gibbs. This is a must read.

I couldn't put this book down! Great story with lots of twists and turns. If you like stories about adventure, this is the one for you. But be warned: There is quite a lot of gun violence.

This book was so awesome! I can’t stress that enough. Charlie is a 12 year old genius and she has is working with the CIA to find one of Einstein’s equations that could be very dangerous in the wrong hands.If you liked Stuart Gibbs Spy School you would love this book