product will be the equations with which the technologists can begin actual system design. In other words, we are working only on the first theoretical step."

"But the newspaper article said the scientists were affected by a gadget," Scotty objected.

"The article was wrong. Paper covered with mathematical computations can scarcely affect anyone," Hartson Brant said decisively.

Rick stared through the window. The sedan was moving down Constitution Avenue toward 14th Street. "But how did the newspaper find out anything in the first place?"

Dodd swung the sedan around a truck, then shrugged expressively. "We'd like to know. Columnists have their sources of information. Usually the source isn't close to the inside dope, so most of the columns are pretty inaccurate. A good thing, too, otherwise the enemy would be getting our top-secret information in print all the time. Probably this leak came from someone in the hospital where the team members were taken."

Conversation lapsed until Dodd swung the sedan into a restricted parking place near the corner of 15th and K streets. Then he led the way into an office building. Rick looked around him as they walked to the elevators. It was a typical large office building with an arcade-type lobby. He noticed a haberdashery shop, a barbershop, a florist, a newspaper-tobacco stand, and the entrance to a drug store. The building directory was loaded with names.

In the elevator, Dodd said, "Four, please."

The Spindrifters were the only ones that got off at that floor. As the door slid closed, Rick saw that a man was seated in an alcove, just out of sight of anyone who got off the elevator. Dodd greeted him, then said, "Remember these faces, Sam."

Sam nodded without speaking.

Dodd led them down a hall. Rick had to satisfy his curiosity. "Is this a government building?"

"No. It's a regular office building. We leased this floor under the name of a phony corporation. It's entirely ours, but the rest of the building is occupied by legitimate firms."

"Isn't that risky?" Weiss asked.

"It depends. If the project is penetrated, then it becomes easier for the enemy in one way, since we don't have the protection of a government building. On the other hand, the public has free access to all but a few of the government buildings, while we can control who comes in and out of this floor."

"What does 'penetrated' mean?" Scotty inquired.

"Known to the enemy."

"But couldn't you have put the project in the Pentagon, or in the Atomic Energy Commission Building?" Rick pursued.

"Yes, except that it's top secret, even within the government. I doubt that more than two dozen people even know about it. Remember, the best security is not to let people even suspect that a thing exists."

"But the project has been penetrated," Scotty pointed out.

"We don't know that. The newspaper article gave no details, remember. Only that some unidentified scientists had gone insane. No location, no names, no anything of real value. And we have taken precautions. After all, you have the team chief. Only one man is left, and we hope to get him out of here, too."

Dodd swung open a door that opened into a bare outer office, and led them into an inner room where a man bent over a desk.

Rick knew his name. This was Dr. Humphrey Marks, the reluctant bachelor. All Rick could see for the moment was a bald head. It was completely bald, not even a fringe of hair remaining. It gleamed in the light of the desk lamp. Presently the bald pate revolved back and a truculent face stared up at them.

Dr. Marks looked like a man who had been born impatient. His underslung jaw thrust forward as he demanded, "Well, well? What is this, Dodd? Well? Who are these people?"

Dodd was unperturbed. "Dr. Brant, Dr. Weiss, and Richard Brant and Donald Scott."

Marks harrumphed. He stood erect, and he was scarcely taller than little Julius Weiss. He had a solid, square build and massive hands. "I am honored, gentlemen," he said crisply. "Sit down."

The Spindrifters did so. "We will get to business," Marks stated. "You will forgive me if I begin on an elementary level. It is only for the purpose of defining the problem. Ames said you had been briefed by Miller, so I will confine the briefing to my part of the project."

Hartson Brant and Julius Weiss produced notebooks. Rick and Scotty relaxed as best they could in the uncomfortable chairs and prepared to listen.

"You are, of course, aware of the problems inherent in the development of inertial systems," Marks began. "Perturbations are many, and both predictable and random. Consider our missile. We set its little brain for a given pattern. We depend on its inertia to inform the brain when perturbations are pulling it off course. The brain then takes the necessary corrective action. This, of course, is oversimplification."

It wasn't very simple to Rick. He squirmed uncomfortably on the hard chair.

"Now, we have dealt primarily with the perturbations one would expect. The equatorial bulge, for example. The result? We still have a probable error of several miles in hitting the target. This is not to be borne, gentlemen. We must have precision. Now, what information do we have that allows such precision? We have the effects of perturbation of the other planetary bodies and of the sun itself. These we may calculate closely. We shall use them to guide our missile, as they interact with the missile's own inertia."

Marks broke off to glare at Rick. He inquired acidly, "Do I perhaps bore you? Or have you a serious itch? If so, scratch it, for heaven's sake. You are squirming so, I can see only a blur through the corner of my eye."

Hartson Brant came to his son's rescue. He looked at Dodd. "May the boys be excused? I'm sure this discussion will be of no value to them, and probably they have some things they would like to do."

Dodd nodded. "If you decide to leave the vicinity, let Sam know."

"We'll be in the lobby," Rick said. He motioned to Scotty. His feelings were of mixed relief at getting out of there and irritation at Marks for what amounted to summary dismissal.

As they walked to the elevator, Rick asked, "What did you make out of that?"

"Not much. How about you?"

"A little," Rick admitted. "Enough to know what the project is aiming at."

"Which is?"

"A guidance system for the intercontinental missile, and a fantastic one that uses the moon and the sun, and maybe Venus and Mars as guideposts."

Scotty whistled. "As you said, a lot of good we'll be to this project. Well, what do we do now?"

Rick ran a hand through his hair. "Follow Barby's instructions." His sister had said bluntly that both he and Scotty were getting as shaggy as Dismal, and please get haircuts. He knew why, of course. Barby wanted them to be at their best, because she liked Jan Morrison very much and wanted Jan to like the boys, too.

Sam nodded to them as they walked to the elevator. Rick noted that the guard could watch the stairs as well as the elevator doors. He also noted that the guard's coat was loose, and that the butt of a Magnum revolver was within easy reach of his hand. Knowing how Steve Ames operated, Rick also suspected that other, less visible, methods had been taken to guard the fourth floor, but there was nothing he could see.

It was still early in the day and the barbershop in the lobby was not crowded. Rick and Scotty both were able to get chairs.

Rick browsed through a magazine as the barber worked, but found nothing of interest. He put it down and looked around him. The shop was like any other shop, anywhere. He thought that barbershops may vary in the number of chairs, the