He was an all-Canadian whiz kid, a celebrated rocket-engineering prodigy, who wanted to make this country a serious player in the 1960s space race. But when science sidestepped Gerald Bull’s plan to build gargantuan guns that could launch projectiles into orbit, he just … broke. He turned his brilliance in missile design to darker pursuits, building horrible weapons for sinister regimes. If it sounds like a spy novel, it ends like one too, with Bull meeting a violent, mysterious end of his own.