Threaded through its unseen but undeniable presence are a thousand, a million — a thousand million — tiny thought-waves flowing out, slamming back, physically manifested in attitudes of body, tones of voice, reflections in eyes and features. These personal physical giveaways can be controlled by strong-willed characters. Clever actors can, and do, stimulate and simulate atmosphere as a part of their craft.

Experienced operatives in the profession of organizational agent train themselves to receive these unseen influences of atmosphere. A good agent could be called a natural intuitive. This isn't merely a person who plays hunches. His skill is far more exact. It is almost a science. His training also develops a swift and sharply defining observation, similar to that of a top detective. Add this to his acute and finely tuned sensitivity to atmosphere, combined with physical alertness, and you have the formula for a successful top agent. Throw in the backing of a world-powerful organization, and you have a formidable opponent at any level of action.

The Padracks and Cheval were excellent actors. They projected no atmosphere through any physical expression. But to April Dancer and Mark Slate it was there as an emanating source strong enough to confirm that Andre Cheval was not only linked to the Padracks — they had already proved this by the decoy action on the island — but also was superior to them.

This meant that THRUSH had four levels of its operatives aboard Island Traveller, with Cheval on the top echelon; certainly not inferior to the Padracks, nor to Maleski. And if he was a scientist, he would be in the executive bracket. This placed the Padracks in field administration over Maleski, who would be in THRUSH'S personnel and field coordinating slot. At the fourth and lowest level were the hand picked toughies — the slog and sluggem boys, no doubt with their assigned leaders under Maleski.

The affair had at last assumed the true pattern of a THRUSH project. These four levels aboard Island Traveller were the nucleus of organization in depth. This was how THRUSH worked. Had to work. A small project of local irritation, or disruption of order, required only a field team of local wreckers. But in a large project they created their operation cells in self-contained units, each linking more closely as the project developed until all were in the end merged.

The nucleus thus expanded, though its nature and purpose did not change. The point at which these merged would be the production end of the project. When this was geared to its maximum, the results would be handled by the distribution or actual attacking forces already set up through their own nucleus centres. Mr. Waverly had intimated that such an organization might well be in existence through the apparently innocent coracle clubs. But this might be a false trail, laid especially for the purpose of diverting attention from the true purpose of the project.

April and Mark used the radio silence period to intensify their thoughts and clarify their future plans. The Padracks were leaving the ship at Taradata. Reports had shown they sometimes stayed over until Island Traveller returned on its next outward trip — sometimes they rejoined when the ship checked in on its return trip. The latter call was in a three-day period. The next outward trip would be in three to five weeks. Would Cheval also stay over in Taradata?

Taradata was a pinhead island compared with some of the others. Even Lagelo, the next port of call, was larger and, by all accounts of the researchers, welcomed visitors, as apposed to Taradata, where they did not. Lagelo was a cultured place, owning a fine library and bookshop. Why should Padrack, the bookman, concentrate on Taradata? Perhaps because Lagelo already had been converted to the written word. Assume the book business to be a front, and you had Taradata smack in your sights as a THRUSH production centre. Because Padrack was THRUSH before he was a bookman. Just as April was U.N.C.L,E. before she was a playgirl. Simple as that.

H.Q. would naturally be collating all reports and coming up with a similar result. The next directive to agents would be an S.F.D. April and Mark already were making their own plans to seek, find, and destroy. But proof wasn't yet conclusive. And even U.N.C.L.E. agents cannot proceed to blow up or otherwise disrupt a peaceful island without cause. Final decisions as to timing and method were often theirs, but Island Traveller was not Del Floria's dry-cleaning shop in the shadow of New York's United Nations building, where U.N.C.L.E.'S eyes and ears of the world poured in their proof — or non-proof — and where Mr. Waverly would press the appropriate button according to the measurement of that proof.

So when radio contact again opened, their own atmosphere was one of anticipation and preparedness. They raised Sama Paru in the midget sub at midnight.

"We are surfaced in a cave beyond Taramao Point," said Sama Paru. "It is very beautiful. A silver moon is spiked upon the black-barbed heads of the trees of the forests of the night. The sea is a whispering mirror around us, lapping the golden sands below the blood-red rocks."

"Oh, Gawd!" Mark exclaimed. "Skip the commercial and tell us why you're there."

Randy Kovac came in with a chuckle. "It's gone to his head — a sort of tropic fever, I guess. We've come direct from Mr. Waverly's naval H.Q. and are waiting for Count Kazan and the launch to rendezvous with us here."

"For what purpose?" April asked.

"Observation of coastline, and to chart depth and currents in possible landing areas, apart from the main beaches and harbour. The far side of the island has an unbroken coral reef off-shore. No boat could cross it without being ripped apart."

Mark said: "Do you have any information of landing parties by the Navy?"

"Mr. Waverly did not specify that action," said Randy Kovac.

"Don't you start!" Mark snapped. "The word 'no' would have been quite sufficient."

April asked: "Did you meet the launch? Did Kazan deliver a passenger to Mr. Waverly?"

"I'll say he did! Wow! What a dish! Are all researchers like her?" Randy Kovac fairly bubbled.

"They're usually old, fat and greasy," said Mark. "Why didn't the launch come with you?"

"The Navy doctor was treating Kazan and Carlson."

"Were they sick or injured?"

Sama Paru said: "I have never seen such colds. Poor Kazan — he was so full of cold he could not speak! Wheezing, sneezing, shivering — you would not believe such a cold could be caught in this climate. Carlson was not quite so bad. He is a big man, and he was coughing like a foghorn. Colamina Sherez was one sad lady — all red-nosed and red- eyed."

"Gosh, I'm sorry!" said April. "Tropical colds can be quite bad, but they don't usually last long."

"Get the infra-red camera quickly!" Sama Pam's voice sounded urgent.

Mark and April waited silently after Sama broke off conversation. He came back in a few minutes.

"The maps we have do not show any habitation on Taramao Point — only a forest of small trees running inland, curving down to a valley. But we have just seen lights flickering from there. Randy has taken photos. I have looked through the night glasses. The flickering is caused by the trees moving. The lights are stationary — like a door or windows opening and closing to release light."

"A signal?" said Mark. "Is Island Traveller visible to you?"

"No — we cannot see your lights. Wait, now — Randy is checking instruments. There is something else — standby."

Again they waited. Later Sama Paru said: "An engine — or more than one — we have picked up the vibrations. There is also a thudding — rhythmic, like small regular explosions."