"How far?" They heard Sama asking Randy to check instruments and telling him how to obtain readings.

"Two miles, landward," said Sama. "We are about three hundred yards off-shore. The beach shelves deeply towards us so we cannot get closer. Even the launch could not."

"Have you any frogmen's gear on board?"

"Yes, four shallow-water outfits. But we must not leave the sub until the launch arrives and you also are at Taradata. Those are orders."

"Okay," said April. "Use your time to survey all of the coastline you can. Make a note of any likely landing spots. Randy — what's all this about your special maps?"

"The researchers' plan maps and the regular maps don't tally. Someone's lost a whole section of the island. The contour lines don't tally."

"And you went on record with your own maps?"

"Yes, Miss Dancer." Randy Kovac sounded apprehensive. His grand ambition was to be an agent. Napoleon Solo and Illya Kuryakin were his heroes, Mark Slate his idol, but woman-wise and agent-wise, April Dancer was his goddess. To please her was to feel the gods smile upon him. To fail her would be stark tragedy.

"Well, if you believe you are right, you should say so," said April cheerfully. "We rely on you back-room boys not to work blindly. The researchers could be wrong. There can't be many modern maps of this part of the world, and they might be too old and badly drawn."

"Oh, they are!" said Randy eagerly. "Indeed they are, Miss Dancer." He laughed ruefully. "Mr. Waverly said that only doughnuts had pieces out of the middle — not islands — so I would be assigned to Mr. Paru for field progress work to check my own figures — so — so here I am."

"Welcome to the rat-race." Mark was friendly. "Sama, did Kazan mention Cheval?"

"Colamina did. Kazan lost his voice. I too remember the name Chaminal. He once went to the Arctic with some expedition to study stresses on the human body — something like that. And he was the man who identified the little bug a few years ago, before we were overrun by an influenza epidemic. Yes — I know of him. A clever man, I think. But these scientists — there are so many. I couldn't say exactly what he is."

"He's not been mixed up in any trouble in Europe?"

"Not to my knowledge."

April's communicator began bleeping.

"Contact out," said Mark to Sama. "H.Q. is on."

April said: "Yes, sir?"

"Ah, Miss Dancer! Is Mr. Slate with you?"

"Here, sir," said Mark. "We've been talking to the D.X.5."

"Good — then you know why the launch is delayed. It is now on its way, Kazan and Carlson having received maximum dosages to help relieve their considerable sufferings. Miss Sherez is aboard here — likewise affected. It is on this matter I call you."

"Yes, sir?"

"You will remember the phial Miss Sherez obtained as sample of contents of boxes now on your ship?"

"I remember," said Mark.

"Mr. Kazan foolishly opened this phial — gently sniffing at the contents, trying to assess its purpose. Mr. Carlson and Miss Sherez also — er — hmm — had a sniff! We have just analysed the contents. They are the most vicious cold virus you could ever wish to meet. That is, if one ever wishes so to do.

"The point is that it appears highly probable that all the boxes contain the same contents. Moreover, we have ascertained that a large quantity of a similar virus, suspended in a jelly, was reported missing from a government research centre close to the Mexican border."

"Reported missing?" said April. "Did they think it walked out?"

"Laboratory jargonese," said Mr. Waverly. "Undoubtedly it was pinched. It appears to have been packed into phials by someone who knew that extreme heat would melt the jelly and make the virus an uncontrollable mass. The jelly has, in fact, melted in the phial. These virus multiply in heat. And as long as they stay in a warm atmosphere, they will continue to multiply. Each phial — if broken — will be a near-lethal bomb in its effect upon those closest to it, who will at once inhale a vast concentration of the virus. Do you follow me?"

Mark said: "Mr. Waverly, sir — we are an astonishing way ahead of you!"

"I thought you might be," said Mr. Waverly. "Do I need to add that there is no possible way of giving immunization? The effects can be treated, but severely dosed persons would die of congestion before penicillin or other drugs could have any effect. In such a concentration of virus, a mask is some protection. But — as our expert says — it would be as much help as a paper tissue against cigarette smoke. In other words — if you devise a mask to prevent the virus entering mouth and nose, you will suffocate yourself."

"A gas mask?" April suggested. "Or smoke mask?"

"In time, perhaps," said Mr. Waverly. "They have been experimenting on such an appliance for about ten years. In another ten, perhaps…"

"And a ruddy great 'tishoo' to you too!" Mark muttered.

Mr. Waverly overheard it. "Levity will not solve our immediate problem, Mr. Slate. These virus cannot be destroyed by water. Once released, they will be drawn up by the sun, multiply even more in heat, and travel with the breeze. A crucible heat might be effective, but the phials would explode and crack the container — it would need experts to carry it out in specially controlled conditions. I doubt if any exist on the Island Traveller, in which these boxes of phials now repose. In fact, we could say you are indeed sitting on them right now."

"We hadn't overlooked the fact," said April. "What are your orders, sir?"

"In the circumstances, Miss Dancer, I have no alternative but to issue an open directive for the guidance of all agents assigned to this project. You now are operating on S.F.D. directive. We are standing by to aid you in any way we can. Seek, find, and destroy. Good luck to you!"

April looked at Mark.

"D'you have a hanky?" he said. "I feel a sneeze coming on."

CHAPTER SEVEN: COOPERATION PLUS

THE enemy — and THRUSH forever was the enemy — in the form of Lucy Padrack had, through personal weakness, betrayed the presence of an operative cell aboard Island Traveller.

The personal weaknesses of April Dancer and Mark Slate lost them much of the advantage they had gained. Perhaps the word "weakness" is unfair. No one told the passengers the E.T.A. of Island Traveller at Taradata. Most passengers didn't care. The islands were off the rat-race routes of the world. Most people were merely seeking sun and fun — not timetables. Mark made his own estimation, but they should have checked. They didn't.

They slept too late. No radio calls through ear and pillow receivers disturbed them. They reached the dawn-gilded deck in time to see the flat-decked harbour launch bobbing shorewards. On the launch were the Padracks, Cheval, and a cluster of boxes.

"S. and F.," said Mark glumly. "But D.? Not this time."

"Let's not feel too bad," said April. "We agreed last night that, short of calling in the Navy, we couldn't capture the ship single-handed. And we couldn't chuck the boxes overboard, even if we'd battled our way to the hold."

"But we could have tried. We just slept." Mark cussed softly as Chas came towards them. "So your V.I.P.s have special treatment, huh?"

Chas peered shorewards. "Who — them? They always get taken off first."