you aren't right," his son continued. "You say you find me—changed. When did you first notice a difference?" "Last night, you were still my little boy. This morning—" Blake Hartley was talking more to himself than to Allan. "I don't know. You were unusually silent at breakfast. And come to think of it, there was something ... something strange ... about you when I saw you in the hall, upstairs.... Allan!" he burst out, vehemently. "What has happened to you?" Allan Hartley felt a twinge of pain. What his father was going through was almost what he, himself, had endured, in the first few minutes after waking. "I wish I could be sure, myself, Dad," he said. "You see, when I woke, this morning, I hadn't the least recollection of anything I'd done yesterday. August 4, 1945, that is," he specified. "I was positively convinced that I was a man of forty-three, and my last memory was of lying on a stretcher, injured by a bomb explosion. And I was equally convinced that this had happened in 1975." "Huh?" His father straightened. "Did you say nineteen seventy-five?" He thought for a moment. "That's right; in 1975, you will be forty-three. A bomb, you say?" Allan nodded. "During the siege of Buffalo, in the Third World War," he said, "I was a captain in G5—Scientific Warfare, General Staff. There'd been a transpolar air invasion of Canada, and I'd been sent to the front to check on service failures of a new lubricating oil for combat equipment. A week after I got there, Ottawa fell, and the retreat started. We made a stand at Buffalo, and that was where I copped it. I remember being picked up, and getting a narcotic injection. The next thing I knew, I was in bed, upstairs, and it was 1945 again, and I was back in my own little thirteen-year-old body." "Oh, Allan, you just had a nightmare to end nightmares!" his father assured him, laughing a trifle too heartily. "That's all!" "That was one of the first things I thought of. I had to reject it; it just wouldn't fit the facts. Look; a normal dream is part of the dreamer's own physical brain, isn't it? Well, here is a part about two thousand per cent greater than the whole from which it was taken. Which is absurd." "You mean all this Battle of Buffalo stuff? That's easy. All the radio commentators have been harping on the horrors of World War III, and you couldn't have avoided hearing some of it. You just have an undigested chunk of H. V.