McGuire was fascinated, and his thoughts raced wildly in speculation of what might be transpiring before his eyes. People, living in that tropical world; living and going through their daily routine under that cloud-filled sky where the sun was never seen. The margin of light that made the clear shape of a half-moon marked their daylight and dark; there was one small dot of light forming just beyond that margin. It penetrated the dark side. And it grew, as he watched, to a bright patch. "What is that?" he inquired abstractedly--his thoughts were still filled with those beings of his imagination. "There is a light that extends into the dark part. It is spreading--" * * * * * He found himself thrust roughly aside as Professor Sykes applied a more understanding eye to the instrument. The professor whirled abruptly to his assistant. "Phone Professor Giles," he said sharply; "he is working on the reflector. Tell him to get a photograph of Venus at once; the cloud envelope is broken." He returned hurriedly to his observations. One hand sketched on a waiting pad. "Markings!" he said exultantly. "If it would only hold!... There, it is closing ... gone...." His hand was quiet now upon the paper, but where he had marked was a crude sketch of what might have been an island. It was "L" shaped; sharply bent. "Whew!" breathed Professor Sykes and looked up for a moment. "Now that was interesting." "You saw through?" asked McGuire eagerly. "Glimpsed the surface?--an island?" The scientist's face relaxed. "Don't jump to conclusions," he told the aviator: "we are not ready to make a geography of Venus quite yet. But we shall know that mark if we ever see it again. I hardly think they had time to get a picture. * * * * * "And now there is only a matter of three hours for observation: I must watch every minute. Stay here if you wish. But," he added, "don't let your imagination run wild. Some eruption, perhaps, this we have seen--an ignition of gasses in the upper air--who knows? But don't connect this with your mysterious ship. If the ship is a menace, if it means war, that is your field of action, not mine. And you will be fighting with someone on Earth. It must be that some country has gained a big lead in aeronautics. Now I must get to work." "I'll not wait," said McGuire. "I will start for the field; get there by daylight, if I can find my way down that road in the dark." "Thanks a lot." He paused a moment before concluding slowly: "And in spite of what you say, Professor, I believe that we will have something to get together on again in this matter."