The most brilliant part of the Alex Rider books is that they are written in a hard hitting, adult style that is incrementally tweaked to adjust to younger readers (for example, the print is still slightly larger than adult books). Horowitz is the master of writing the Reluctant Hero; we get tantalizingly small doses of Alex's ordinary life before he is taken off on yet another mission. Even though he is reluctant, he is fantastically good at his job, and wants to make things right in the world. The twists and turns of the adults' forays into counter espionage, as well as Mrs. Jones' backstory, add another interesting layer to this. Nightshade is a new organization for Alex to take down, and it seems like there will be another book to deal with them. As always, the details about jumping out of planes, evading security, and being on the run are well drawn and intriguing. It won't be long before MI6 finds that many of its recruits will cite Stormbreaker (2000) as their impetus for joining the secret service!
While this series is great for fourth grade and up, this book had a little more human-on-human violence than the others. Freddy is very vicious, so this starts out with more brutal killings than most books. This does, however, serve to highlight Alex's compassion and dislike for killing.
There are four series in my library that I make sure are being held together by whatever means necessary: Horowitz's Stormbreaker, Ally Carter's Gallagher Girls, John Flanagan's Ranger's Apprentice, and Shan's Cirque du Freak. I don't know that I could work in a library that didn't have the complete Stormbreaker series. Just couldn't. I have told my daughters that my personal copy of Secret Weapon must always stay with me; I'll need it to be handing it to people who visit me when I am very old and still thinking I am a school librarian!