factions had been responsible for some of the most fiendish plots ever perpetrated against the Swifts.

"Unfortunately, that's not all," Thurston went on. "Interpol believes that Narko is also a member of the same rebel outfit with whom you've had trouble before."

Tom was dismayed by the news. "I sure thought that group had been smashed!" he said. Soon after Tom had balked their attempts to seize the satellite Nestria, the rebel ringleaders had reportedly been arrested and tried for treason.

"It now appears," Thurston explained, "that only one segment was quelled. Other members of the antigovernment movement are active again and are said to be strongly organized."

The CIA man related even more sinister news. It was suspected that a larger nation—by aiding the rebels—was planning a coup to take over Brungaria. They had already subverted various government agencies and were sending their own professors to staff the Brungarian technical schools. It was all part of their insidious fifth-column pattern.

"Many top Brungarian officials have joined the plotters," Thurston added, "and it's now becoming very difficult for anyone to enter or leave the country."

Ames asked for information on any rebel sympathizers known to be in the United States. Thurston was able to tell him very little.

"We keep strict tabs, of course, on all Brungarians entering this country," Thurston explained. "But even though we screen them carefully, a rebel agent like Narko may slip in—usually on a stolen or faked passport."

When the telecast ended, Tom, Bud, and Ames discussed the news grimly.

"What if Narko has pals working with him?" Bud conjectured.

"If he does," Tom said, "they may try carrying through Narko's mission."

"I'll station extra guards around the outer wall on twenty-four-hour alert," Ames promised.

Tom approved this measure wholeheartedly, but the purpose of Narko's secret mission remained a mystery. Why had he tried to force his way into Enterprises? What was he after? There was little hope of resolving these questions, since United States Intelligence had learned of the rebel movement itself only within the past few days. Thurston had asked Tom and his companions to treat the information as confidential.

"I'd better get back to work," Tom decided after Bud and Ames had left his office. Tom sat down at his drawing board and began to sketch out some rough ideas for a vehicle to house the "brain energy" from space.

Tom wondered if the brain would be able to perform actions by itself, given the proper mechanical output devices. Or would he have to help it function via an electronic computer to digest incoming information or stimuli and then to respond through servo controls?

The problem was so baffling and complex that Tom became completely oblivious to the passage of time. He sketched out plan after plan, only to crumple and discard each one.

Suddenly a disturbing thought jarred the young inventor out of his concentration. Perhaps the Brungarian rebel scientists had now figured out how to decode the radio messages from the Swifts' space friends!

If so, when the brain energy was launched toward earth, they might try to divert it to their own receiving setup!

CHAPTER IV

ANOTHER TREMOR!

Tom was appalled at this new danger. Shoving his drawing board back into its wall slot, the young inventor hurried to his desk and made a number of telephone calls.

Within minutes, a group of five of his most trusted associates had assembled in Tom's office. First to arrive were Bud Barclay, Ames, and George Dilling, the Swifts' communications chief. They were joined moments later by Hank Sterling, the square-jawed chief engineer and trouble shooter of Enterprises, and Arvid Hanson.

Hanson, a hulking six-footer, made all the delicate scale models of Tom Jr.'s and Tom Sr.'s inventions. He was not only an expert craftsman, but, like all the Swifts' key men, a trained aircraft and space pilot as well.

"What's up, skipper?" Bud asked.

"I guess you might call this a council of war," Tom replied.

He divulged his fears that Brungarian scientists might hijack the brain energy to be sent from Planet X, home of the Swifts' unknown space friends.

"Bud, you recall Mother's remark last night about the danger that this energy may prove overwhelmingly powerful," Tom went on. "Well, just suppose that our Brungarian pals fit it out in robot form, then turn it loose against us or our friends in other countries."

Bud gave an awed whistle. "Boy, a thing like that might make even a powerful missile look like a toy!"

Even if the brain energy proved too small to be harnessed for destructive purposes, Tom went on, it might turn out to possess superintelligence. Gifted with all the scientific know-how of the space people, it might be made to reveal those secrets to the Brungarians.

"They might learn from it how to construct weapons or space craft powerful enough to conquer the free world!" Tom ended.

His listeners were grim-faced at the thought.

"I'd say that's a far worse danger than any chance of their coming up with a robot monster," Ames said.

"Ditto!" Hanson agreed.

"I think so too," Tom replied. "In any case, it's up to us to make sure the Brungarians don't switch that energy off course before it lands here."

"Think their scientists are capable of such a stunt?" George Dilling inquired.

Tom shrugged. "They're certainly far advanced in the fields of rocket guidance and telemetry. But actually we just don't know."

Hank Sterling glanced hopefully at the young inventor. "Got any ideas, skipper?" he asked.

Tom drummed a pencil on the table thoughtfully before replying. "Maybe our best bet is first to find out all we can about the lines of research on which they're concentrating. That might be the tip-off."

After a thorough discussion, it was decided that Ames and Dilling would fly to Washington at once and talk to the FBI and Central Intelligence. Their job would be to garner and piece together every scrap of information on Brungarian scientists' accomplishments.

"Let us know as soon as you get a general picture," Tom said.

Ames and Dilling promised to do so, and the meeting broke up.

Feeling somewhat reassured now that a definite plan of action had been decided upon, Tom resumed work on his sketches. Although both the problem and the solution were still hazy in his mind, a few ideas began to take shape.

A radio antenna would certainly be needed, to receive or transmit signals at a distance. And repelatron units would give the brain a way to exert force when it wanted to act. These were devices which Tom had invented to produce a repulsion-force ray. He had used the principle in both air and space flight.

A power plant might also be needed to generate additional energy in case the brain's own energy was very small. Lastly, there would have to be a control system for use either by the brain itself or by its human operators.

After an hour of work at top speed, Tom was rather pleased with one rough sketch. He was mulling over the idea when Chow Winkler and Bud Barclay wandered into the office. Both were impressed when Tom explained the sketch.

Chow stared at it, goggle-eyed at the thought of such a contraption "coming to life." "So that's the Ole Think Box, eh?" he muttered.

Tom laughed. "Good name, Chow!"