The third man from the Earth Committee, Mr. Wallace, seldom spoke. When he did, his voice was mild, and there was a sense of child-like wonder in his tone. "The natives?" he asked.
"They ... had fled when we discovered the city."
"Where did they flee to?" Mr. Wallace asked.
Captain Meford glanced upward. Other eyes followed to end just below the edge of the view screen. Above stood the sheer face of the cliff. Clouds roiled below the summit, obscuring it from view.
"There is a long sloping plateau up there, and a series of natural caves back in the next cliff face," Captain Meford said. This did not seem adequate. He continued: "Most of the air-changing activity starts in the low-lying areas, at first around the dome positions. It advances along an elevation front, gradually drifting up. Little tongues are carried up in advance by the heated currents. The aliens retreated before it. On the plateau you can see the sentries. I guess they posted themselves there, at intervals, between the edge and the new caves, to define the limits of safety. They died there. Six of them. The rest, several hundred, reached the caves. They are dead, too."
"I see," Mr. Wallace said.
"When you first discovered them—?" Mr. Ryan asked after a moment.
Captain Meford hesitated.
Mr. Tucker said: "I believe one of your men killed himself last night—wasn't it? A technician? I was told he felt you could reverse the air-changing equipment in time to save the aliens. I understand that was very much on his mind for the last week or so."