I looked at him blankly. "Invasion? What invasion?" "One from out in space," he said casually. "You know, one from another planet or another star. That type of invasion." I sat there letting my coffee grow cold because all the time I was thinking that the one thing in the world John Kelley didn't possess was a sense of humor. As long as I had known him he had never told a joke and came damn close to never laughing at any. "I don't recall any reports of anybody running around with six arms or green skin or tentacles instead of limbs," I protested mildly. * * * * * He shook his head, deadly serious. "You're not looking at it logically, Charley. The only beings who would be interested in the planet in the first place are beings who could live here. And if they could live here, then it's possible they could have the same sort of physical make-up." He paused. "Maybe the exact same sort of physical make-up. Even to the extent of the average man's desire to avoid trouble." Kelley had something there. Every time you think of an invasion from outer space, you think of a hundred huge rocket ships settling down with ray guns going full blast and king-sized atomic bombs breaking up the landscape. Actually, of course, it doesn't have to be like that at all. Granted a physical resemblance in the first place, then maybe it wouldn't be an invasion. It might be more of an ... infiltration. I jerked my thumb towards the people who crowded around the train gates and sprawled out on the benches. "You mean that some of those people aren't ... genuine?" "That's right," John said slowly. "Some of them aren't the real McCoy." I watched the people for a moment more, staring hard at the old man buying a paper at the newsstand and the old woman who was selling it to him. "How can you tell which are which?" "I can't. So far as I know, there isn't any way." He had forgotten his coffee now. It sat at his elbow, an unappetizing mixture of lukewarm grounds, cigarette ash, and disintegrated doughnut. "Any leads?" "You've been reading them every day, Charley. A dozen times a year somebody sees flashes in the sky, a dozen times lights settle down in relatively uninhabited sections of the country. Sure, people see them and report them. And what happens?" He shrugged. "The papers treat them as part of the silly season, readers only glance at the reports. You know as well as I that nobody packs up a camera to go out and investigate." I took another look around the station. The bored people, sitting on benches and reading their papers. The mother with her baby, sleeping now but one you knew would be squalling in a few minutes. The porter sweeping up just in front of the wash-room. The man in the information booth rifling through a stack of time-tables. All very prosaic all very every dayish. I turned back to Kelley, my face showing disbelief. "You don't believe me, do you?" I turned up my hands. "It's a pretty big order, John."