Elias Mercer stood in his antique shop, the winter darkness pressing against the windows at 6 PM. Nearing closing time, he was wrapping an old book when the doorbell chimed. He looked up, spotting a figure shrouded in shadow. The stranger stepped inside, the dim light revealing nothing but a silhouette. A chill crept through the room as Elias's instincts sharpened. "Can I help you?" he asked, sensing that this was no ordinary visitor.