I yanked Theo up the stairs and slammed the door. He cried, then calmed down, then asked a question that froze me solid. "Why does the other Theo get to stay down there?" he said. "He looks just like me. He's still counting." I held him tight and didn't answer. But that night, and every night since, I hear two boys counting under the floor, and I'm too scared to check which one is mine.