Alex is the 14-year-old protagonist of the novel. He grew up in the Chelsea area of West London with his uncle Ian and housekeeper, Jack Starbright. Never having known his parents, who died when he was an infant, Alex bonded with Ian and Jack. Ian taught him sports and outdoor skills including soccer, karate, diving, skiing, motorbike riding, parachuting, and even vehicle driving. Because of these talents, Alex is athletic and excels in his spy work when he joins MI6. Alex is also inquisitive and pays attention to detail. He quickly determines that Ian’s death is suspicious, and he easily connects the van to the junkyard, finds his uncle’s car, and determines he was shot. Alex is also perceptive and can tell when people are lying, though he is deceived by Sayle’s charm at first.

Despite his skills, Alex struggles with life as a spy. He wishes he could be a normal teenager and wants the freedom to make his own decisions. He frequently feels like Alan Blunt and Mrs. Jones are using him and resents them for it. As the novel progresses, he is more able to put these feelings aside to stop Sayle. Alex also shows integrity and common sense, such as when he rebukes Sayle for his plan to murder schoolchildren and reminds him that many children have endured bullying, but it does not justify mass murder.