Most weapons do what you tell them. Most weapons you can control. But what if the most dangerous weapon in the world isn't a smart missile or a stealth submarine or even an AI computer programme? What if it's a 17-year-old boy with a blisteringly brilliant mind, who can run rings around the most sophisticated security services across the globe, who can manipulate that weaponry and turn it against the superpowers themselves? How valuable would he be? And what wouldn't you do to get hold of him?