I've 'rode' these books from the beginning to the end, starting in sixth grade. (You see what I did there, don't you?) In my honest opinion, they kept getting better as each one came. Alex grew, and with him, the threats grew as well.
Horowitz did something new with this one! Jack Starbright and Mr. Smithers joined Alex on his mission, because, honestly, all he was doing was going to school, right? I love how Horowitz incorporates the two characters and makes you meet them in a new way.
The end of this book will have you wondering: Who is REALLY the enemy?