I turned back to Adam. "You won't like it," I said. "Maybe not. But I gotta know. I just gotta!" "Not 'gotta'," Ruth corrected automatically. "'Have to'." "I have to know." I paced three more laps, still hesitating. I felt like a surgeon, trying to decide whether or not to operate when it's a toss-up whether the operation will kill the patient or cure him. "All right, Adam," I said wearily. "You win. But you have to promise me something. Promise me that you'll never say anything to the other Kids about what I'm going to tell you." Now it was his turn to weigh a decision, and I could feel the battle going on behind those crystal-clear eyes. His innate honesty, battling with his insatiable curiosity. He considered for perhaps a full minute, then he nodded. "Okay. I don't think it's right not to tell Kids the truth--but I promise." "Cross your heart?" "Cross my heart." I took a deep breath, signalled Ruth to make some coffee, and began. "You were right about Santa Claus, Adam. He's just make-believe, and so are the fairies. Santa Claus was invented by Mommies and Daddies to represent the _spirit_ of Christmas for kids too little to understand its real meaning. People on Earth still observe the holiday, although they've gradually forgotten what it really stands for. I'll explain that part to you later." "What's Earth, Daddy?" "Earth is where everybody lived before there were any spaceships. It's a big place, and some of it's nice and some of it not so nice. The people live in houses, something like this one, and the ones in a house are called families. There's a Mommy and a Daddy for each family, and their kids live in the house with them." "Where do the kids come from?" "From the Mommy. It's the same as what we call 'making a Dolly'." "Oh." * * * * * I talked for six hours, until I was so hoarse my voice was cracking on every other word. He took it all in stride, injecting a question here and there, absorbing it all like an unemotional sponge. But when I began to talk about war, he became a little upset. I explained how it had begun as individual struggles for survival or supremacy in the days of the cavemen, how it had evolved along with society into struggles between families and tribes, then nations, and now--between planets. "But why do they _kill_ each other, Daddy? That doesn't prove anything." I laughed. "Son, if I could answer that one, I'd be Daddy Number One of the whole universe!" * * * * * We finally packed Adam off to bed in the spare room, after promising him we'd talk some more the next night. I'd shown him my library and told him he could come and read any time he liked, though of course he mustn't take any books out of the house where the Kids might see them. Ruth and I stood on the front porch for awhile in the moonlight, gazing out over our once-peaceful little world. "Harry, what will become of him?"