The Recruit (Cherub, Band 1)

CHERUB agents are all seventeen and under. They wear skate tees and hemp, and look like regular kids. But they're not. They are trained professionals who are sent out on missions to spy on terrorists and international drug dealers. CHERUB agents hack into computers, bug entire houses, and download crucial documents. It is a highly dangerous job. For their safety, these agents DO NOT EXIST.
James is the latest CHERUB recruit. He and his sister were recently orphaned, and James has been in a lot of trouble. But he is brilliant in math. And CHERUB needs him. After one hundred days, the grueling training period is over. But the adventure has just begun.