Skeleton Key

Skeleton Key is an adventure novel by Anthony Horowitz, published in 2002 and the third book in the Alex Rider series. It follows Stormbreaker and Point Blanc, and it sends its fourteen-year-old protagonist into a country that has been closed to the outside world.

Alex is attached to an operation that pretends to be a holiday tennis camp on an island off Cuba, where a former Russian general named Alexei Sarov has taken over a facility. Sarov's plan involves a weapon left behind by the Soviet Union and a demonstration he intends to make, and the novel turns into a race to stop it, with Alex inside the compound and nobody able to help him.

Horowitz uses the island setting to keep the action contained, and the book has the same structure as the rest of the series: Alex is placed somewhere he does not belong and has to work out who can be trusted. It was followed by further volumes, and it is one of the entries where the villain's motive is political rather than criminal.