Alfred Egner drowned. He was just a workhorse, really, a 19-year-old boy from Munich, hired by a couple of former SS officers in 1963 to dive down to the murky bottoms of Austria's Lake Toplitz and resurface with fistfuls of treasures secreted away in this alpine paradise. It wasn't his first dive in Lake Toplitz, but he may have gotten tangled in some of the hundreds of logs that line the bottom, or something may have gone wrong with his equipment. Regardless, he never retrieved what the two men were most likely looking for: secret codes to Swiss bank accounts,...