Alex Rider is an agent with MI6.
He is also a 14-year old male who never expected, nor wanted, to become a spy and would likely have looked at you oddly if you had suggested it. Nevertheless, life, and the death of someone close to him, forced the issue and pushed the teenage boy into growing up far too fast.
His parents, John and Helen Rider, died in a plane crash just a few months after Alex Rider was born. Though Rider would not learn of it for many years, his father had been a distinguished agent with MI6 for many years, codename Hunter, and it was that service that would cost the couple their lives. Infant Alex went to live with his uncle, Ian Rider, who became the only parent the youngster would know.
Uncle Ian shared something with his brother - he, too, was an MI6 agent. Using a cover identity as the overseas financial manager for the Royal & General Bank, his trips around the globe on behalf of his employer gave him terrific camouflage for the clandestine work. When he was old enough to travel with his uncle, Alex Rider became a junior citizen of the world himself, learning what life was like in numerous parts of the globe.
He also learned a wide assortment of skills from his uncle as they shared a love of adventure and outdoors activity. Hiking, camping, rock climbing, sailing, scuba diving, and more the two did in exotic lands and at home. He loved his life.
He found he was particularly good with languages. He could grasp a culture and a way of speaking and feel totally at home with it quickly, a talent that made his times in different countries even more pleasurable and would aid him greatly when it came time for his work with British Intelligence.
That arrived with the murder of his uncle. That man's death when Rider was 14 nearly shattered the boy but the resilience instilled in him came through and when the opportunity to fight back came, or more accurately forced its way in, Rider was ready. Well, mostly.
As the series progresses, Rider, a student at the Brookland School in London, lives with his legal guardian, Jack Starbright (don't let the masculine name fool you), and takes the odd mission or two, when exams allow, for not only MI6 but also, less commonly, for the CIA. He gains insight into those who killed first his parents and then his uncle and he finds a way to exact justice.