"I'll scout around a bit and see what I can find," he said.

It was not until lunch was nearly over that she was able to detach her mind from the baby. Then she asked, "Oh, Peter, what happened with Commander Towers?"

"He'd got a draft operation order," he told her. "I suppose it's confidential, so don't talk about it. They want us to make a fairly long cruise in the Pacific. Panama, San Diego, San Francisco, Seattle, Dutch Harbor, and home, probably by way of Hawaii. It's all a bit vague just at present."

She was uncertain of her geography. "That's an awfully long way, isn't it?"

"It's quite a way," he said. "I don't think we shall do it all. Dwight's very much against going into the Gulf of Panama because he hasn't got a clue about the minefields, and if we don't go there that cuts off thousands of miles. But even so, it's quite a way."

"How long would it take?" she asked.

"I haven't worked it out exactly. Probably about two months. You see," he explained, "you can't set a direct course, say for San Diego. He wants to keep the underwater time down to a minimum. That means we set course east on a safe latitude steaming on the surface till we're two-thirds of the way across the South Pacific, and then go straight north till we come to California. It makes a dog leg of it, but it means less time submerged."

"How long would you be submerged, Peter?"

"Twenty-seven days, he reckons."

"That's an awfully long time, isn't it?"

"It's quite long. It's not a record, or anywhere near it. Still, it's quite a time to be without fresh air. Nearly a month."

"When would you be starting?"

"Well, I don't know that. The original idea was that we'd get away about the middle of next month, but now we've got this bloody measles in the ship. We can't go until we're clear of that."

"Have there been any more cases?"

"One more-the day before yesterday. The surgeon seems to think that's probably the last. If he's right we might be cleared to go about the end of the month. If not-if there's another one-it'll be sometime in March."

"That means that you'd be back here sometime in June?"

"I should think so. We'll be clear of measles by the tenth of March whatever happens. That means we'd be back here by the tenth of June."

The mention of measles had aroused anxiety in her again. "I do hope Jennifer doesn't get it."

They spent a domestic afternoon in their own garden. Peter started on the job of taking down the tree. It was not a very large tree, and he had little difficulty in sawing it half through and pulling it over with a rope so that it fell along the lawn and not on to the house. By teatime he had lopped its branches and stacked them away to be burned in the winter, and he had got well on with sawing the green wood up into logs. Mary came with the baby, newly wakened from her afternoon sleep, and laid a rug out on the lawn and put the baby on it. She went back into the house to fetch a tray of tea things; when she returned the baby was ten feet from the rug trying to eat a bit of bark. She scolded her husband and set him to watch his child while she went in for the kettle.

"It's no good," she said. "We'll have to have that playpen."

He nodded. "I'm going up to town tomorrow morning," he said. "We've got a date at the Navy Department, but after that I should be free. I'll go to Myers' and see if they've still got them there."

"I do hope they have. I don't know what we'll do if we can't get one."

"We could put a belt round her waist and tether her to a peg stuck in the ground."

"We couldn't, Peter!" she said indignantly. "She'd wind it round her neck and strangle herself!"

He mollified her, accustomed to the charge of being a heartless father. They spent the next hour playing with their baby on the grass in the warm sun, encouraging it to crawl about the lawn. Finally Mary took it indoors to bathe it and give it its supper, while Peter went on sawing up the logs.

He met his captain next morning in the Navy Department, and together they were shown into the office of the First Naval Member, who had a captain from the Operations Division with him. He greeted them cordially, and made them sit down. "Well now," he said. "You've had a look at the draft operation order that we sent you down?"

"I made a very careful study of it, sir," said the captain.

"What's your general reaction?"

"Minefields," Dwight said. "Some of the objectives that you name would almost certainly be mined." The admiral nodded. "We have full information on Pearl Harbor and on the approaches to Seattle. We have nothing on any of the others."

They discussed the order in some detail for a time. Finally the admiral leaned back in his chair. "Well, that gives me the general picture. That's what I wanted." He paused. "Now, you'd better know what this is all about.

"Wishful thinking," he observed. "There's a school of thought among the scientists, a section of them, who consider that this atmospheric radioactivity may be dissipating-decreasing in intensity, fairly quickly. The general argument is that the precipitation during this last winter in the Northern Hemisphere, the rain and snow, may have washed the air, so to speak." The American nodded. "According to that theory, the radioactive elements in the atmosphere will be falling to the ground, or to the sea, more quickly than we had anticipated. In that case the ground masses of the Northern Hemisphere would continue to be uninhabitable for many centuries, but the transfer of radioactivity to us would be progressively decreased. In that case life-human life-might continue to go on down here, or at any rate in Antarctica. Professor Jorgensen holds that view very strongly."

He paused. "Well, that's the bare bones of the theory. Most of the scientists disagree, and think that Jorgensen is optimistic. Because of the majority opinion nothing has been said about this on the wireless broadcasting, and we've been spared the press. It's no good raising people's hopes without foundation. But clearly, it's a matter that must be investigated."

"I see that, sir," Dwight said. "It's very important. That's really the main object of this cruise?"

The admiral nodded. "That's right. If Jorgensen is correct, as you go north from the equator the atmospheric radioactivity should be steady for a time and then begin to decrease. I don't say at once, but at some point a decrease should be evident. That's why we want you to go as far north in the Pacific as you can, to Kodiak and to Dutch Harbor. If Jorgensen is right, there should be much less radioactivity up there. It might even be near normal. In that case, you might be able to go out on deck." He paused. "On shore, of course, ground radioactivity would still be intense. But out at sea, life might be possible."

Peter asked, "Is there any experimental support for this yet, sir?"

The admiral shook his head. "Not much. The Air Force sent out a machine the other day. Did you hear about that?"

"No, sir."

"Well, they sent out a Victor bomber with a full load of fuel. It flew from Perth due north and got as far as the China Sea, about latitude thirty north, somewhere south of Shanghai, before it had to turn back. That's not far enough for the scientists, but it was as far as the machine could go. The evidence they got was inconclusive. Atmospheric radioactivity was still increasing, but towards the northern end of the flight it was increasing slowly." He smiled. "I understand the back-room boys are still arguing about it. Jorgensen, of course, claims it as his victory. He says there'll be a positive reduction by the time you get to latitude fifty or sixty."

"Sixty," the captain said. "We can make that close inshore in the Gulf of Alaska. The only thing up there is that we'd have to watch the ice."

They discussed the technicalities of the operation again for a time. It was decided that protective clothing should be carried in the submarine to permit one or two men to go on deck in moderate conditions and that decontamination sprays should be arranged in one of the escape chambers. An inflatable rubber dinghy would be carried in the superstructure, and the new directional aerial would be mounted on the after periscope.

Finally the admiral said, "Well, that clears the decks so far as we are concerned. I think the next step is that I call a conference with C.S.I.R.O. and anybody else who may be concerned. I'll arrange that for next week. In the meantime, Commander, you might see the Third Naval Member or one of his officers about this dockyard work. I'd like to see you get away by the end of next month."

Dwight said, "I think that should be possible, sir. There's not a lot of work in this. The only thing might hold us up would be the measles."

The admiral laughed shortly. "The fate of human life upon the world at stake, and we're stuck with the measles! All right, Captain-I know you'll do your best."

When they left the office Dwight and Peter separated, Dwight to call the Third Naval Member's office, and Peter to go to find John Osborne in his office in Albert Street. He told the scientist what he had learned that morning. "I know all about Jorgensen," Mr. Osborne said impatiently. "The old man's crackers. It's just wishful thinking."

"You don't think much of what the aeroplane found out-the reduced rate of increase of the radioactivity as you go north?"

"I don't dispute the evidence. The Jorgensen effect may well exist. Probably it does. But nobody but Jorgensen thinks that it's significant."

Peter got to his feet. "I'll leave the wise to wrangle," he quoted sardonically. "I've got to go and buy a playpen for my eldest unmarried daughter."

"Where are you going to for that?"

"Myers'."

The scientist got up from his chair. "I'll come with you. I've got something in Elizabeth Street I'd like to show you."

He would not tell the naval officer what it was. They walked together down the centre of the traffic-free streets to the motorcar district of the town, turned up a side street, and then into a mews. John Osborne produced a key from his pocket, unlocked the double doors of a building, and pushed them open.