She Sheltered 15 Strangers in a Blizzard. The Next Day, a Roar of Engines Returned—And She Feared She Had Made a Mistake...//...The silence that settled over the valley after the blizzard was usually Agnes Porter’s favorite sound. It was the sound of peace, of a world sleeping under a heavy white blanket. But tonight, that silence felt heavy, charged with an electricity that made the hair on her arms stand up. Agnes Porter, a seventy-eight-year-old widow who had lived on these rugged Montana out