"Yes, I do," he admitted, "and so does father. But I cannot go into it now with you. You see," he added hastily, as though he feared to hurt my feelings, "the scientific men of Mercury--some of them--objected to Miela's coming, on the ground that the inhabitants of the earth, obtaining from her a knowledge that would enable them to voyage through space, might take advantage of that knowledge to undertake an invasion of Mercury. "As a matter of fact, that was a remote possibility. I could explain to you all I know about this mechanism without much danger of your ever being able to build such a car. But Miela promised them that she would use all possible precautions, in the event of her having any choice in the matter, to prevent the earth people learning anything about it. "Father and I have examined everything here closely. But no one else has--and I am sure Miela would prefer no one else did. You understand, Bob?" I did understand; and of course I had to be satisfied with that. "It seems to me," I said when, later in the day, we were discussing affairs in Wyoming, "that with things in Mercury as we now know they are, it would help the situation tremendously if Tao and these Twilight People with him were prevented from ever returning." "That's my idea exactly," Professor Newland agreed. I could see by the look on his face he was holding on to this thought as a possibility that might make Alan's plan unnecessary. "I've thought about it constantly," the professor said, "ever since these facts first came to us through Miela. It would be important. With his expedition here a total failure, I think we might assume that nothing more would be done up there in attempting to conquer the earth. I've tried to make Alan see that we should give the authorities all the information we have. It might help--something might be accomplished--" "Nothing would, father," Alan interrupted. "There wouldn't be time. And even if this expedition of Tao's were destroyed, I don't see why that's any guarantee another attempt would not be made. Miela doesn't, either, and she ought to know. "Besides, don't you see, Bob"--he turned to me earnestly--"I can't have the eyes of the world turned on Miela and her affairs? Why, think of it--this little woman sent to Washington, questioned, photographed, written about, made sport of, perhaps, in the newspapers! And all for nothing. It is unthinkable." "You may be right, my boy," said the professor sadly. "I am giving in to you, but I still--" "The thing has come to me," said Alan. "A duty--a responsibility put squarely up to me. I've accepted it. I'll do my best all the way." A week after Alan and Miela were married the report came that the Mercutians had suddenly departed, abandoning, after partly destroying, their apparatus. The world for a few days was in trepidation, fearing a report that they had landed somewhere else, but no such report came. Three days later Alan and Miela followed them into space.