Reviewed by Nathaniel S. (age 9)
I think this book is good because it is a mystery and you figure out some of it in the end. My favorite part is when the children's guardian Hector shows them his secret library. The three characters I liked were Violet, Klaus and Sunny. Violet reminded me of one of my brothers because he is almost always inventing things. You can figure out some of what will happen but to figure it all out, you have to read all the books in the series.
I recommend this book for third to tenth graders because it might be to hard for first and second grade and it might be boring for eleventh and twelfth.