Beyond the pond, about thirty yards from the laboratory, a laminated steel fence had been erected with signs suggesting that a curious person would be treated with considerable displeasure.

But the fence did not conceal entirely the scaffolding inside it, which rose almost as high as that of an oil well.

Illya continued across the bridge and passed through the doors of the laboratory, where he was greeted by a red-headed receptionist whose eyes reflected their appreciation for Illya's blond, steel-eyed good looks.

She announced him to the lady who was expecting him, and with disappointment showed him to an inner office and turned him over to Frieda Winter.

Her official title, according to the lettering on her door, was assistant director of experimental projects, and Illya, thinking in stereotypes, had expected a stout woman with mousy hair, horn-rimmed glasses and a white smock that would display about as much figure as a pup tent.

If he was disappointed, it certainly didn't show in the warm glow that spread over his cheeks as his eyes took her in. She was, for a laboratory worker and administrator, quite a dish. Her hair was dark auburn, almost black with red highlights, and her eyes hazel and round and intense. She wore no smock at all, but a red skirt with matching sweater that revealed a splendid figure.

During the course of conversation Illya Kuryakin managed to sneak a look at her ankles, hoping to find some disfigurement that would release him from having to be interested in Frieda Winter the woman, and enable him to pay the strictest attention to Frieda Winter the scientist. But her ankles were as well-turned as any item of fine furniture.

Evidently she was thinking much the same thing about him, for she said, "I somehow expected a Dick Tracy hat and the rest of the G-Man bit."

Illya smiled boyishly. "No, the investigative offices have become very cool these days. I mean, we try to be cool. It makes our enemies think we're not scared to death. It also," he added, "makes women think we're not terribly interested in them."

"I suppose that's a good thing, professionally speaking."

"Professionally speaking," Illya said. They exchanged glances, then Illya dropped his eyes, sighed, and said, "Suppose we speak professionally then."

"Yes." She walked to her desk and sat down. "How much do you know about Dr. Dacian and his work?"

"Quite a lot, but suppose you tell me everything, from the way he was hired to the events of the last day you saw him. Then I'd like you to show me the apparatus and explain its operation to me as completely as you can. I have more technical knowledge than you think, but quite a lot less than I'd like to have, so speak to me like a colleague but don't be surprised when I ask some incredibly stupid questions."

She smiled. Then, after ordering coffee from the laboratory cafeteria, she began to tell Illya all about the engagement of Edward Dacian by Gulf Coast Power and Light.

It had been well known that Gulf Coast was experimenting with the idea of tapping the heat beneath the mantle of the earth to produce cheap electricity, and Dacian had read about the lab's work in a journal. Their experiments corresponded to some he had been performing at Colorado School of Mining, but the school simply couldn't put at his disposal the kind of financial backing he needed to explore his ideas to their logical conclusion. Thus he got in touch with Gulf Coast and was hired.

Within eight months he had constructed a laser of enormous power, operating on light transmitted through gas instead of crystal and using a system of "mirrors" which were made of opaque liquids contained in saucer-shaped crystal containers.

The liquids intensified the laser beam terrifically, but their formula was known only to Dr. Dacian, and they constituted the essence of his earth-piercing apparatus.

"Dr. Dacian," Frieda Winter explained, "learned that the beam works most effectively in already-existing shafts. The beam, in other words, is poor at starting a hole, but if it operates in a well the walls of the shaft contain the potency of the beam. The beam works faster the deeper the shaft. We ascertained that it took the beam twenty-four hours to dig through the first two thousand feet of surface, twelve hours to pierce the next two thousand, and so on almost in geometric proportions."

"In other words, it would take about forty-eight hours to penetrate the mantle in a land formation of average depth, but only about two if the beam were sent down a shaft the depth, say, of an average oil well."

The girl looked at him with admiration.

"It didn't take very long for you to calculate that," she said.

"In most things I think fast. Now tell me, was Dr. Dacian's progress publicized?"

"Only by word of mouth. We tried to prevent official publicity and tried to stop gossip, but unfortunately people aren't made that way, and I imagine somebody got loose-tongued over a drink. I assure you it wasn't I," she said quickly.

"You needn't be defensive," the U.N.C.L.E. agent assured her. "Now I'd like you to tell me, or check for me, whether during this time any suspicious individuals came to work for your company. It stands to reason that the persons most suspect are those who quit their jobs around the same time as Dacian disappeared."

Frieda Winter handed Illya Kuryakin a slim file. "You'll find in there the records of six people who joined the company, in capacities ranging from janitor to executive, and left in a period ranging from two weeks before to two weeks after Dr. Dacian's disappearance. Everyone else has been checked thoroughly or is under surveillance, but these six have not been located."

Illya removed six smaller envelopes from the file and opened each, removing neatly arranged dossiers on the individuals in question. They contained, among other things, a photograph of the person, used on identification badges or cards which all personnel were required to carry with them at all times.

Illya, one of whose duties was to brief himself regularly on the faces of his antagonists, glanced quickly at each picture, studying it and comparing it with a mental image in his brain's rogue's gallery.

On the fifth photo his eyes widened. The bony face, the angular Adam's apple, the unusual grey scar on the brow, tallied with a face Illya knew.

He studied the accompanying documents: Paul Rollins, alias Rawlings and a few other pseudonyms, had come to work for Gulf Coast as a groundskeeper. His employers had not bothered to check on background or references for such an inconsequential job, but after Dacian's disappearance an investigation had disclosed that Rollins had been involved in a number of criminal activities and had a prison record. He had also been arraigned on a kidnapping charge but his case had been dismissed for lack of evidence.

"This looks like our man," Illya said.

"Most likely it is," Frieda said. "The F.B.I. agrees and is already putting a search out for him. And incidentally—"

Illya anticipated her question. "I work for a different outfit," he explained, "and all I can tell you is that we're good guys, just like the F.B.I. But we aren't too chummy with those fellows, and besides, our records are often more complete than theirs."

"I see."

"I would like to transit this material to my superior officers so that they can run routine checks on the other five, but I would especially like to find out as much as possible about this Rollins. Perhaps during lunch—."

"As much as we know about him is in that envelope," Frieda said lugubriously. "But perhaps we can find another excuse for lunch."