Scorpia rising by Anthony Horowitz
Alex Rider Book 9. Walker Books, 2011. ISBN 9781406333879.
(Age: 14+) Highly recommended. Alex Rider is a teenage superspy. But he hates it. Alex just wants to live like a normal teenager, but whenever that chance appears, MI6 seems to have a mission for him. But this time, Alex and Jack Starbright (his friend, and the woman who had cared for him since his parents died) are adamant that MI6 would never be a part of their lives again. But a snipershooting at his school wounded his friend and almost kills Alex, and all is changed. Everyone is convinced that his old enemy, Scorpia, is out for revenge. MI6 recently discovered evidence that Scorpia might be planning to hold some children for ransom at an international school in Cairo and because some of these children's parents could pay millions of dollars in ransom they decide to send Alex there. The old security man was killed, and replaced at the same time as Alex.
This is an excellent end to an excellent series, and I recommend that you make sure you have read all the books before this one. You can pick this one up easily, but it does help, as you might not know what Scorpia is if you have not read the previous series. I enjoyed this book, and I highly recommend this book, and the entire series.