And Etl could at least ape the outward aspects of the thoughts and feelings of men. There were things he said to me that were characteristic, though they came out of apparent sullenness that, for all I knew, had seeds of murder in it: "You're my pal, Nolan. Sort of my uncle. I won't say my father; you wouldn't like that." Nice, embarrassing sentiment, on the surface. Maybe it was just cool mimicry--a keen mind adding up human ways from observation of me and my kids, and making up something that sounded the same, without being the same at all. Yet somehow I hoped that Etl was sincere. Almost from the building of the cage, of course, we'd kept photographs and drawings of Mars inside for Etl to see. Hundreds of times I had said to him things like: "It's a ninety-nine and ninety-nine hundredths per cent probability that your race lives on that world, Etl. Before the ship that brought you crashed on Earth, we weren't at all sure that it was inhabited, and it's still an awful mystery. I guess maybe you'll want to go there. Maybe you'll help us make contact and establish amicable relations with the inhabitants--if there's any way we can do that." During those five years, no more ships came to Earth from space, as far as we knew. I guessed that the Martians understood how supremely hard it would be to make friendly contact between the peoples of two worlds that had always been separate. There was difference of form, and certainly difference of esthetic concepts. Of custom, nothing could be the same. We didn't have even an inkling of what the Martian civilization would be like. * * * * * One thing happened during the third year of Etl's existence. And his presence on Earth was responsible. Enough serious interest in space travel was built up to overcome the human inertia that had counteracted the long-standing knowledge that such things were possible. A hydrogen-fusion reaction motor was built into a rocket, which was then hurled to the moon. Miller went along, ostensibly to help establish the first Army experimental station there, but mostly to acquire the practical experience for a far longer leap. In a way, I wished I could have gone, too; but, after all, the shadows in Etl's background were far more intriguing than the dead and airless craters and plains of the lunar surface. Before Miller and the other moon-voyagers even returned, Detroit was busy forging, casting and machining the parts for a better, larger and much longer-range rocket, to be assembled in White Sands, New Mexico. When Miller got back, he was too eager and busy to say much about the moon. For the next two and a half years, he was mostly out in White Sands.