"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." "I'm not too familiar with the man, sir. He was on Captain Arnold's shift, I believe." "Captain Meford," Mr. Ryan insisted, "when did you say you first discovered the aliens?" Captain Meford hesitated. The others waited. "They were then scaling the cliff, sir." "And General Shorter, was he told of this immediately?" Mr. Ryan asked. "I don't know when the general was told." "You discovered them?" "Yes, sir. I ... you see, at the time the winds completely prohibited air traffic. As you know, the air scouts are not stable enough until ... later. Later, I ... Yes, sir. I discovered them." "Did you then inform the general?" "No, sir. I informed the duty officer." "Did he inform the general?" "I don't know." "Why didn't you tell the general?" Mr. Tucker asked. "I was then in communication with Captain Geiger, and I felt he...." The sentence trailed away. "Would tell the general?" Mr. Tucker prompted. "Well, did he?" "I believe he did, sir," Captain Meford said. He let out a long breath. "May we see the aliens?" Mr. Ryan asked. "I wouldn't advise it, sir," Captain Meford said. "High flights are still very risky because of the wind velocities." * * * * * After the evening meal, General Shorter called Captain Arnold aside. "Mind if I go over to Nine with you?" he asked. "The air around here is--well, the fact of the matter is, I'd like to get away from them for awhile." "Of course not, sir," Captain Arnold said. "We'll call it an inspection. Which might be a good idea at that. With these people running around trying to interfere with my schedule. Poking around. Asking questions. Taking men away from their work, basically." He tapped his teeth with his right thumb in reflection. "I'd better check up on all the domes tonight, just to be sure." "Yes, sir." "I wouldn't want anything to go wrong because they're here."