The idea for “They” came to me on a winter evening at twilight when I peered out my living room window toward a snowstorm, only to be surprised by shadows moving behind the veil of snow. Low shadows. Swift. Large. At once, they were gone. Probably just my imagination, I decided. A trick of the fading light. Or maybe the shadows belonged to some dogs running past my house, eager to get out of the storm. But then my imagination kicked in. What if the shadows were real and belonged to something I needed to be afraid of, and what if I lived in something far less sturdy than the room from which I watched the shadows?