ARK ANGEL by Anthony Horowitz is another excellent adventure with everyone's reluctant teenage spy, Alex Rider.
I would personally suggest reading SCORPIA before you read this latest installment in the Alex Rider series, because they are particularly linked.
By the end of Scorpia, Alex has suffered a nearly fatal wound and is in the hospital recovering from surgery when he meets young Paul Drevin. When four thugs show up in the hospital attempting to kidnap young Drevin, Alex is once again pulled into a web of international intrigue and espionage.
This latest Alex Rider has a different flavor from the previous, but was still excellent. Horowitz never ceases to find new ways of getting Rider into peril and then barely getting him out of it again. One of the more interesting elements concerning this series is the fact that Alex is ever the "Reluctant Spy" who somehow gets entangled with each new adventure against his will. Another highly recommended adddition to this young adult favorite!