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?" "A device set there by an intelligent being, and set a long time ago. This valley wasn't arranged over night, six months ago--or even a year ago. We'll have to let the experts tell us when and for what reason. Now, let's head for home!" He brought the flitter up and over the valley wall, flying southwest so that they passed over the gap which was the main entrance to the trap. And now he tried the com unit, endeavoring to pick up a signal on which they could beam in for a safe ride. "That's odd." Under Hume's control the direction finder passed back and forth without bringing any answering code click from the mike. "We may be too far in the mountains to pick up the beam. I wonder...." He swept the needle in another direction, slightly to the left. A crackle spat from the mike. Vye could not read code but the very fury and intensity of that sound suggested panic--even terror. "What's that?" Hume spoke without looking away from the control board. "Alarm." "From the safari?" "No. Wass." For a long second Hume sat very still, his fingers quiet. The flitter was on the automatic course, taking them out of the mountains, and Vye thought that their air speed was such they were already well removed from that sinister valley. Hume made a slight adjustment to a dial, and the flitter banked, coming around on another course. Once more he spun the finder of the com. This time he was answered with a series of well-spaced clicks which lacked the urgency of that other call. Hume listened until the code rattled into silence again. "They're all right at the safari camp." "But Wass is in trouble. So what does that matter?" Vye wanted to know. "It matters this much." Hume spoke slowly as if he must convince himself as well as Vye. "I'm the Guild man on Jumala, and the Guild man is responsible for all civs."