It isn’t the known we fear most. The known, no matter how horrible or perilous to life and limb, is something we can wrap our brains around. We can always respond to the known. We can draw plans against it. We can learn its weaknesses and defeat it. We can recover from its assaults. So simple a thing as a bullet might suffice. But the unknown, it slips through our fingers, as insubstantial as fog.