SANTA BARBARA, Calif. - The boys were halfway across a snowfield when the German airplane appeared. Their rifles, clumsily camouflaged, were sticking out of their backpacks. They stood frozen as the plane buzzed in tighter and tighter circles around them, wondering if they should run for the only possible shelter, a large boulder in the middle of the field. It might finally have been curtains for the Kavli boys, Fred and Aslak. "If we'd run, we would have been done for," Fred Kavli, 77, recalled recently, his head thrown back as he communed with memories of an adventurous youth in...