The book is about teenage spy Alex Rider, and it is good for boys AND girls. Alex is a spy for MI6, who is nearly killed in a toxic lab by its evil owner, and charity owner. Then he is kidnapped and tortured, and he has to stop a plague killing thousands.
This book is suitable for people 9-12. Mr Horowitz could have done this in first person as it would be effective. This book, more than his others, involves a lot of feelings.