What are the motifs in Stormbreaker by Anthony Horowitz?

Espionage is a recurring idea. Ian Rider is a spy for MI6 and it is this occupation that leads to his death. Alex has always believed his uncle works for a bank and that his frequent trips are related to that occupation. When Ian dies, however, Alex quickly becomes aware of oddities in the behavior and actions of his uncle's co-workers. This soon leads Alex to seek out the truth and to discover his uncle's true occupation.