Lucky said, "I get the picture. Now get to the point"

"The point is overconfidence, Mr. Starr. We've partitioned off the dangerous sector, but how strong is the partition? We always counted on the outer wall's going gradually, springing a small leak. The water would trickle in, and we always knew that we would have plenty of time to get ready for it. No one ever thought that someday a lock might be opened wide. The water will come in like a fat steel bar moving a mile a second. It will hit the sectional transite barrier like a spaceship at full acceleration."

"You mean it won't hold?"

"I mean no one has ever worked out the problem. No one has ever computed the forces involved-until half an hour ago. Then I did, just to occupy my time while all this is going on. I had my computer. I always have it with me. So I made a few assumptions and went to work."

"And it won't hold?"

"I'm not certain. I don't know how good some of my assumptions are, but I think it won't hold. I think it won't. So what do we do? If the barrier doesn't hold, Aphrodite is done. The whole city. You and I and a quarter of a million people. Everybody. Those crowds outside that are so excited and thrilled are doomed once that man's hand pulls downward on the switch it holds."

Lucky was staring at the man with horror. "How long have you known this?"

The engineer blurted in immediate self-defense,

"Half an hour. But what can I do? We can't put subsea suits on a quarter of a million people! I was thinking of talking to Morriss and maybe getting some of the important people in town protected, or some of the women and children. I wouldn't know how to pick which ones to save, but maybe something should be done. What do you think?"

"I'm not sure."

The engineer went on, harrowed. "I thought maybe I could put on a suit and get out of here. Get out of the city altogether. There won't be proper guards at the exits at a time like this."

Lucky backed away from the quivering engineer, his eyes narrowed. "Great Galaxy! I've been blind!"

And he turned and dashed out of the room, his mind tingled with a desperate thought.

Bigman felt dizzily helpless in the confusion. Hanging as closely as he could to the coattails of the restless Morriss, he found himself trotting from group to group, listening to breathless conversations which he did not always understand because of his ignorance about Venus.

Morriss had no opportunity to rest. Each new minute brought a new man, a new report, a new decision. It was only twenty minutes since Bigman had run off after Morriss, and already a dozen plans had been proposed and discarded.

One man, just returned from the threatened sector, was saying with pounding breath, "They've got the spy rays trained on him, and we can make him out. He's just sitting with the lever in his hand. We beamed his wife's voice in at him through the etherics, then through the public-address system, then through loudspeaker from outside. I don't think he hears her. At least he doesn't move."

Bigman bit his lip. What would Lucky do if he were here? The first thought that had occurred to Bigman was to get behind the man-Poppnoe, his name was-and shoot him down. But that was the first thought everyone had had, and it had been instantly discarded. The man at the lever had closed himself off, and the dome-control chambers were carefully designed to prevent any form of tampering. Each entrance was thoroughly wired, the alarms being internally powered. That precaution was now working in reverse-to Aphrodite's peril rather than its protection.

At the first clang, at the first signal gleam, Bigman was sure, the lever would be driven home and Venus's ocean would charge inward upon Aphrodite. It could not be risked while evacuation was incomplete.

Someone had suggested poison gas, but Morriss had shaken his head without explanations. Bigman thought he knew what the Venusian must be thinking. The man at the lever was not sick or mad or malevolent, but under mental control. That fact meant that there were two enemies. The man at the lever, considered by himself, might weaken from the gas past the point where he would be physically capable of pulling the lever, but before that the weakening would be reflected in his mind, and the- men in control would work their tool's arm muscles quickly enough.

"What are they waiting for, anyway?" growled Mor-. riss under his breath, while the perspiration rolled down his cheeks in streams. "If I could only train an atom cannon at the spot."

Bigman knew why that was impossible, too. An atom cannon trained to hit the man from the closest approach possible would require enough power to go through a quarter mile of architecture and would damage the dome enough to bring on the very danger they were trying to avoid.

He thought, Where is Lucky, anyway? Aloud he said, "If you can't get this fellow, what about the controls?"

"What do you mean?" said Morris.

"I mean, gimmick the lever. It takes power to open the lock, doesn't it? What if the power is cut?"

"Nice thought, Bigman. But each lock has its own emergency power generator on the spot."

"Can't it be closed off from anywhere?"

"How? He's closed off in there, with every cubic foot set off with alarms."

Bigman looked up and, in vision, seemed to see the mighty ocean that covered them. He said, "This is a closed-in city, like on Mars. We've got to pump air all over. Don't you do that, too?"

Morriss brought a handkerchief to his forehead and wiped it slowly. He stared at the little Martian. "The ventilating ducts?"

"Yes. There's got to be one to that place with the lock, doesn't there?"

"Of course."

"And isn't there someplace along the line where a wire can be wrenched loose or cut or something?"

"Wait a while. A microbomb shoved along the duct, instead of the poison gas we were talking about"

"That's not sure enough," said Bigman impatiently. "Send a man. You need big ducts for an underwater city, don't you? Won't they hold a man?"

"They're not as big as all that," said Morriss.

Bigman swallowed painfully. It cost him a great deal to make the next statement. "I'm not as big as all that, either. Maybe I'll fit."

And Morriss, staring down wide-eyed at the pint-size Martian, said, "Venus! You might. You might! Come with me!"

From the appearance of the streets of Aphrodite, it seemed as though not a man or woman or child in the city was sleeping. Just outside the transite partition and surrounding the "rescue headquarters" building, people choked every avenue and turned them into black masses of chattering humanity. Chains had been set up, and behind them policemen with stunguns paced restlessly.

Lucky, having emerged from rescue headquarters at what amounted to a dead run, was brought up sharply by those chains. A hundred impressions burst in on him. There was the brilliant sign in lucite curlicues, set high in Aphrodite's sky with no visible support. It turned slowly and said: aphrodite, beauty spot of venus, welcomes You.

Close by, a line of men were moving on in file. They were carrying odd objects-stuffed brief cases, jewel boxes, clothes slung over their arms. One by one, they were climbing into skimmers. It was obvious who and what they were: escapees from within the threatened zone, passing through the lock with whatever they could carry that seemed most important to them. The evacuation was obviously well under way. There were no women and children in the line.

Lucky shouted to a passing policeman, "Is there a skimmer I can use?"

The policeman looked up. "No, sir, all being used."

Lucky said impatiently, "Council business."

"Can't help it. Every skimmer in town is being used for those guys." His thumb jerked toward the moving file of men in the middle distance.