"Night coming." Which was true. Then Hume added, "If we can reach the flitter before sunset, we'll have a chance to fly over the lake down there, to make a taping of it before we go."
The energy of the tablets strengthened them so that by the time they reached the crevice door they were moving with their former agility. For a single second Hume hesitated before that slit, almost as if he feared the test he must make. Then he stepped forward and this time into freedom.
They reached the ledge where the flitter perched just as they had seen it last. How long ago that had been they could not have told, but they suspected that days of haze hung in between. Vye searched the sky. No globes winking there—just the flyer alone.
He took his old seat behind the pilot, watched Hume test the relays and responses in the quick run down of a man who has done this chore many times before. But the other gave a little sigh of relief when he finished.
"She's all right, we can lift."
Again they both looked aloft, half fearing to see those malignant herders wink into being to forbid flight. But the sky was as serenely clear of even a drifting cloud as they could hope. Hume pressed a button and they arose vertically with an even progress totally unlike the leap which had taken them out of Wass' camp.
Well above the cliff wall they hovered, and were able to see below the round bowl of the valley prison. Hume touched controls, the flitter descended slowly just above the center of the lake. And from this position they were able to sight the other peculiarity of that body of water, that it was perfectly oval in shape, far too perfect to be an undeveloped product of nature. Hume took a round disk from his equipment belt, fitted it carefully into a slot on the control board and pressed the button below. Then he sent the flitter in a weaving zigzag course well above the surface of the water, so that eventually the flyer passed over every foot of its surface.
And from above, in spite of the turgid quality of the liquid, they could see what did rest on the bottom of that oval. The wall with its sharp corner which Vye had noted from shore level was only part of a water covered erection. It made a design when seen from overhead, a six-pointed star surrounding an oval and in the midst of that oval a black blot which they could not identify.
Hume brought the flitter over in one last sweep. "That's it. We have a full taping."
"What do you think it is?"