Being CEO of flourishing JK Holdings isn't a sufficient challenge for millionaire restaurateur Justin King. He craves the rush gained by facing danger and triumphing-be it heli-skiing, rappelling, suit jumping from the peaks of Mt. Everest or racing performance cars. But nothing does it for him like breaking into impenetrable fortresses and rifling their vaults for Guardian Security. It's the best-kept secret of his very public life. Danielle Grant...