It started innocent. My daughter would laugh in her room, whispering to someone she called “Mr. Hollow.” When I asked, she said, “He tells me what you dream about.” I brushed it off — until she repeated one of my nightmares word for word. Last night she came to my bed, eyes wide. “Mr. Hollow says he’s not imaginary anymore,” she whispered. Now there are footprints leading from her room to mine, too large to be hers.