Northwest Smith embarks on a dangerous trip to learn the secrets of the moon and a lost civilization.excerpt"I'll bet you the next drinks," murmured Yarol, his wise black eyes twinkling under long lashes, "that you can't guess what race that little fellow's from, or where it originated.""The next drinks are on me anyhow," grinned Smith. "No I can't guess. Does it matter?""Oh-curious, that's, all. I've seen a member of that race only once before in my life, and I'll bet you never saw one. And yet it's an Earth race, perhaps the very oldest. Did you ever hear of the Seles?"Smith shook his head silently, his eyes on the little figure below, which was slowly drawing out of sight beneath the overhang of the terrace on which they sat."They live somewhere in the remotest part of Asia, no one knows exactly where. But they're not Mongolian. It's a pure race, and one that has no counterpart anywhere in the solar system that I ever heard of. I think, even among themselves their origin has been forgotten, though their legends go back so far it makes you dizzy to think of it. They're queerlooking, all white-haired and fragile as glass. Keep very much to themselves, of course. When one ventures out into the world you can be sure it's for some tremendously important reason. Wonder why that fellow--oh well, not that it matters. Only seeing him reminded me of the queer story that's told about them. They have a Secret. No, don't laugh; it's supposed to be something very strange and wonderful, which their race life is dedicated to keeping quiet. I'd give a lot to know what it is, just for curiosity's sake.""None of your business, my boy," said Smith sleepily."Like as not it's better for you that you don't know. These secrets have a way of being uncomfortable things to know.""No such luck," Yarol shrugged. "Let's have another drink-on you, remember-and forget it."