"Snakehead", the latest Alex Rider adventure, follows the 14-year-old super-spy on a treacherous mission to infiltrate ruthless gangs smuggling weapons, drugs and people across Southeast Asia.
In what Anthony Horowitz calls "the most scary chapter I've ever written", Alex is imprisoned at a centre where his body parts are to be removed for transplants.
"What makes it so horrible is the fact that people involved are so charming -- not my usual comical villains, but quite monstrous," Horowitz said in a telephone interview. "It is a very dark chapter."
In "Snakehead" there are clear references to the plight of refugees, tsunamis, the recent Live 8 anti-poverty pop concerts and ethnic tensions in Afghanistan.
"The success of the books is connected in part to the fact that they are always dealing with the real, recognisable world."Horowitz said he would probably wind up the bestselling Rider series at 10 books, meaning three more stories that will take him another five years to complete.