Although he now worked for an international organization, Illya had been born in Russia, and he still retained much of his Slav imperturbability. For all the expression that showed on his smooth, bland face, the girl’s curvaceous figure, pliant waist and the tempting curve of her mouth might have been carved from stone. “Good morning, Viola,” he said politely. “I am afraid I may be a few minutes late. If you would kindly pin on my badge, I’ll go straight up.”

The girl sighed. Like many of the female personnel at the Command’s headquarters, she found Kuryakin’s serene detachment a constant challenge to her femininity. She was sure that if only those sensitive features could be persuaded to relax a little, to warm up…suppressing another sigh, she reached into the top right hand drawer of her desk, took out a small white badge and lingeringly pinned it on his lapel. (The badges were another aspect of security. A red one admitted the wearer only to the ground floor, where day-to-day routine operations were completed. A yellow badge permitted entry to the ground and second floors, where the organization’s communications center was located. And a white one was reserved for those who rated admission to the Policy and Operations Sections on the third. A chemical on the receptionist’s fingertips activated the badge as it was pinned in place—and anyone mounting to a floor higher than his badge allowed automatically tripped a complex alarm system which flashed red lights on every desk in the building and slid steel doors across the passages to trap the intruder.)

Illya found Waverly and Solo in a small room on the second floor lined with gray filing cabinets. A projector and screen were set up in one corner. Pilot lights gleamed from a complicated tape deck housed in a recess beside the door. And there was a single buff cardboard folder on the table in the middle of the room.

A lock of crisp, dark hair had fallen forward over Solo’s alert face, and there was a troubled look in his eyes.

“Ah, Mr. Kuryakin.” Waverly nodded in greeting. “There is work to be done. I think it will save questions afterwards if I take this thing right from the beginning.” He crossed to a door set between two banks of steel cabinets—and threw it open. “If you would be so kind as to join us, gentlemen…”

A plump army officer with a bald head and a hooked nose came into the room, followed by a tall, thin, crewcut man with rimless glasses.

“General Powers from the Pentagon; Mr. Forster from the Central Intelligence Agency.” Waverly made the introductions with a wave of his hand. “Mr. Solo and Mr. Kuryakin are our two top Enforcement Officers.”

They sat down around the table and Waverly dragged a sandblasted briar pipe from the pocket of his baggy jacket. Perhaps you’d like to acquaint these gentlemen with your side of the affair, Mr. Forster,” he said, ramming tobacco into the bowl from an oilskin pouch.

The CIA man cleared his throat. “Certainly. Not much to tell, really—just that there’s been a gradual series of thefts of Uranium 235.”

“Gradual?”

“Over the past three years. We hadn’t paid all that much attention until one of our computers came up with a rundown a couple of months back. We realized then that the method of operation in each case was identical.”

“I should think even one theft of 235 merited a great deal of attention,” Waverly put in dryly.

“Oh, sure. Every one was a big deal. On file, top priority, kept very secret—and all hell breaking loose to try and get the stuff back, identify the thieves.”

“Then…?”

“What I mean is, we—the CIA—hadn’t paid much attention until we realized the thing followed an international pattern.”

“International?” Illya echoed.

“Sure. They lifted the stuff from Hanford, from Clinton, from Calder Hall in England and Dounreay in Scotland; from Chatillion, near Paris, France; and from Magnitogorsk—”

“From Russia!” Solo exclaimed. “If it is a Thrush job, that was certainly a mistake!”

“You mean tipping us off that it wasn’t the other side? Could always have been the Chinese. Or even the Soviets raiding their own places as a blind.”

“Yes, I suppose so. What kind of amounts were involved?”

“Individually, pretty small. But if you add it all together it amounts to quite a bit That’s why we called in your boys when we figured it was a planned series by persons unknown.”

“You’re sure it’s not the Soviets?” Illya asked.

“Absolutely. Why would they bother? They make more than we do.”

“True. And none of it has been recovered?”

“Not an ounce. They were clever operations, all right. Every one an inside job…not a man connected with the thefts identified.”

“With the security setup surrounding nuclear physics, I should have thought that was impossible.”

The CIA man shrugged. “Nothing’s impossible. It happened. The point is—who took it, and why?”

“Perhaps General Powers could enlighten us at least on the latter point,” Waverly intervened. “He’s the thermonuclear expert.”

Powers twitched podgy shoulders to resettle his immaculately cut olive-drab jacket. In contrast to the clipped Bostonian of Forster and Solo’s mid-Atlantic accent, his voice was harsh and twangy with the intonation of the Middle West. “Yeah. Well, I guess you gentlemen have gotten used to the fact that whoever took this U-235 took it for one purpose and one purpose only: to use in the manufacture of thermonuclear bombs.”

Waverly had for some minutes been tamping the tobacco down into the bowl of his pipe with the forefinger of his right hand. Now he laid the pipe down on the table and leaned forward. “That was the obvious conclusion,” he said. “And since nations are very touchy on matters of their own defense—and since, furthermore, there were international ramifications to this affair—our friends at the CIA thought it best to hand the baby over to us, since we are ourselves an international organization. If, on the other hand, it is not some power-hungry nation at work, but Thrush up to its tricks again—then again we know more about their modus operandi than anyone else.”

“Quite. Well, the first thing we have to consider,” General Powers resumed, “is how this stolen material can be used. First of all, we can rule out the crude atom bomb: that’s kid stuff now. Second of all, I figure we can forget the cobalt bomb. Most everybody’s too goddamned scared to touch it. And that leaves us with the conventional thermonuclear fusion bomb…Now, I guess you gentlemen are familiar with the principle of this device?” He looked around the circle of attentive faces and continued before anyone had time to speak: “As you are probably aware, there are three separate explosions involved here—or more properly four, if you count the original detonator. The detonator sets off a charge of conventional explosive which hurls together two quantities of fissile material together adding up to more than that substance’s critical mass. This initiates a chain reaction producing a fission explosion—and it is only in the immense heat generated by this that the fusion process involving the bomb’s main constituents can take place.”

“You mean an H-bomb has to be triggered off by a small A-bomb explosion inside it?” Solo asked.

“Er—yes. If you want to put it like that. Now, the odd thing is,” Powers continued, “that the light elements required for the fusion process—that is, the main explosive substance is an, er, H-bomb—can be acquired by any country or organization with resources. What stops every country in the world going nuclear is the difficulty and expense of obtaining the fissile material involved in the initial atom-bomb blast.”

“And that is—Uranium 235?”

“Or Plutonium 239. Precisely.”

“So that whoever has this stolen Uranium 235—provided they can command reasonable resources—could be setting up a plant and manufacturing H-bombs in some secret place…say somewhere in Africa?”