"Just as paradoxical," he said, shrugging, and taking a huge bite of braised beef tongue. "If you go into the future--or talk to the future--the future affects the change, through you. In other words, if you can't go back into the past, neither can people from the future. And it's inconceivable that such a thing wouldn't make changes. Maybe only small ones, but they'd multiply in time. '_Thou canst not change a flower, without troubling of a star._' That's Francis Thompson. You step on one spider today, and you affect the evolution of spiders, the ecology of all other things in the distant future. By a simple act like that you could destroy or create a whole species to come." "My head swimmeth," I said. "All I want to know is--" He wasn't even listening to me. He enjoyed spouting this kind of thing. "Of course, it's theoretically possible for you to _witness_ events out of the past, without being party to them. If, for instance, you could travel away from Earth at more than the speed of light, overtaking the light waves of an event--say, the Monitor and Merrimac fight--" "Or the Battle of Gettysburg," I said, loyal to the core. "--you could look back and see it happen. The future? I doubt it. Unless in some way time and space actually curve back upon themselves, as some think." "Uh huh," I said, and drank my coffee and finally left Clipper Moskowitz. * * * * * After that I did manage to forget about Zon Twenty temporarily. It was a busy week. The draft quota had gone up, and Personnel Planning had worked out new criteria for classification, and I had to study these to apply them to analysis. This won't make much sense to you unless you've worked in a military headquarters yourself. I worked. I had a dim idea that if I worked hard enough somebody would favorably regard one of my requests to get sent overseas. I've got to explain something right here. I don't want anybody to get the idea I'm a hero type--a professional volunteer. But I'm a career officer, and overseas duty is the quickest way to tactical unit command, which is important on the record. The lack of it has kept many a perfectly good colonel from getting his first star and making that final big step. So I worked hard, and of course, sent in another request for transfer, this time under the provisions of a different set of regulations. And I didn't think about Zon Twenty again until about a week later, one afternoon, when the phone rang. "Personnel Analysis. Colonel Bog--" He didn't even let me finish. "Well! I've found you again! The man from the past!" "Oh, no," I said. "Don't tell me. Not Zon Twenty--" "Yes, it's I, of course! Seems we've had another lucky accident, and been connected again. I was despairing of it for a while. Now, for machine's sake, don't go away this time! I've _got_ to talk to you!" "It's your dime," I said. "Dime!" He pounced on it. "That was a monetary unit, when you had money, wasn't it?" "Look, mister--"