Before Andy High and the construction experts of the National Airways had arrived to supervise the building of the Goliath, Uncle Sam’s newest bid for supremacy in the skies, Bellevue had been a sleepy little village in the heart of the bluegrass section of Kentucky. It had been selected as the construction site for several reasons. One of the most important was its location between two long rows of hills which insured it of protection from high winds. Another was its comparative isolation. There were no main highways leading into the bluegrass town and only one branch line railroad, which, however, was sufficient to handle the shipments of supplies.

The secrecy which shrouded the building of the Goliath was another factor in the selection of Bellevue, for the isolated little village was hard to get to without being seen and it was a comparatively easy thing to guard all entrances to the valley.

Construction headquarters had been set up almost two years before the spring in which the Goliath was scheduled for trial tests. First had come freight trains heavily laden with building materials. A little village of construction houses had gone up alongside the railroad to shelter the workmen whose task it was to build the great hangar which was to house the Goliath.

As mighty as the hangar of the Akron was, that of the Goliath was even larger. It measured 1,400 feet from one of its “orange peel” doors to the other and was broad enough for the Goliath, when completed, to nest comfortably alongside the Los Angeles, when that dirigible hopped over from Lakehurst for a friendly call.

Andy High, son of the vice president of operations of National Airways, had arrived with the first of the construction crews and had hardly left the village during the two intervening years. His father, Charles High, and Capt. John Harkins, who was to be in command of the new sky king, had shuttled back and forth between the assembly plant at Bellevue and the various factories in other cities which were supplying materials which went into the construction. It had been Andy’s duty to stay on the job at Bellevue and see that every part of the carefully organized construction machine kept to its schedule for every day represented thousands of dollars to the National Airways and they made each working minute count.

The hangar had been completed and parts of the dirigible, much of which had been fabricated at the Zeppelin plant at Akron, arrived by the train-load to be assembled in the big dome-shaped shed just outside Bellevue.

On this particular spring morning, Andy was in his office just outside the hangar, pouring over the set of blueprints for the big gondola which was being assembled for the forward end of the dirigible. He was engrossed in the blueprints and failed to hear Bert Benson, who was to be chief radio operator on the Goliath, enter the room.

“Hello, Andy,” said Bert quietly.

The unexpected greeting startled the young aircraft engineer and he jumped involuntarily. When he saw that his visitor was Bert he grinned sheepishly.

“Sorry I jumped like that,” he said, “but we’ve been having so many mishaps in the last two weeks my nerves are on edge.”

“I know it,” replied Bert gravely. “It’s been just one thing after another. First something goes wrong here and then something turns up in another part of the plant. Seems as though there was a hoodoo on this valley.”

“I wouldn’t exactly call it a hoodoo,” said Andy, “but we’ve certainly been having our share of tough breaks. I’ll be glad when Dad and Captain Harkins get back from Akron. Then we’ll be able to give more of our time to closer supervision of the plant and these accidents may be stopped.”

The words were barely out of Andy’s mouth when Bert, who had been looking toward the far end of the hangar, gripped the young engineer hard.

“Look, Andy,” he cried, “one of the doors at the other end of the hangar is opening!”

Andy looked in the direction Bert pointed. There was no mistake. One of the huge “orange peel” doors which sealed the ends of the hangar was swinging back on the railroad track on which it was mounted.

“Something’s gone wrong down there,” said Andy sharply. “A crew is working on top of that door this morning. They may be brushed off if that door isn’t stopped at once.”

Bert realized the danger to men working on the top of the 225 foot, 600 ton door, and he nodded grimly. There was something decidedly wrong, for specific orders had been issued that the doors were never to be opened unless Andy or Capt. Harkins were at the controls of the motors which moved the giant doors.

“Come on,” cried Andy. “We’ve got to stop that door.”

They left the office and jumped into Andy’s roadster which was parked nearby. With a clashing of hastily shifted gears, they roared along the outside of the hangar. While they dashed toward the end, the door continued its slow, relentless movement. At the top they could see a half dozen men clinging to the girders. The control room for the doors was on the other side and Andy whipped his roadster around the end of the hangar. He was out of the machine before it stopped and raced toward the motor room with Bert at his heels.

There was no one at the control board and the powerful motors were humming softly. With one swift movement Andy shut off the power and the great door stopped.

“Run outside and tell that crew on top of the door to hang on for another five minutes,” Andy told Bert. “Warn them to hold on tight when I start rolling the door in.”

The radio operator departed on the run and Andy, looking through a window, saw Bert megaphone with his hands and shout the warning to the desperate crew clinging on top of the door.

Andy threw over the controls and turned on the motors. He let the clutch which operated the door mechanism in easily and the great “orange peel” moved slowly back into place.

While the motors sang at their task, Andy’s mind was busy over this near tragedy. It could not have been an accident by the furthest stretch of the imagination for motors do not start all by themselves and clutches do not jump into place without a guiding hand. In the last two weeks there had been one minor accident after another. It had been maddening. The Goliath was scheduled to make its trial flights in two more months and there wast much remaining to be done. Each little delay meant valuable time lost and Andy had about come to the conclusion that a deliberate attempt was being made to delay the construction of the great ship. He promised himself that there would be a thorough investigation of this latest incident.

The door finally rolled into place and the half dozen men who had been in danger of their lives quickly climbed down to a place of safety.

Andy disengaged the clutch and shut off the motors. Bert returned and they made a thorough inspection of the little room but found nothing which would identify the man who had started the motors.

“Now I’ll tell you why I came into your office,” Bert told Andy after they had securely locked the control room. “Last night someone tampered with my radio equipment and broke up a lot of it.”

Andy’s lips snapped into a thin, straight line.

“How much damage was done?” he asked.

“Not as much as I first feared,” replied Bert. “As luck would have it whoever used the hammer destroyed experimental equipment and the installation for the Goliath is almost intact. He must have been an amateur at the job or he would have singled out the set for the Goliath and smashed it.”

“What you’ve told me and what’s just happened,” said Andy grimly, “makes me positive that there is a well-defined plot under way to injure the Goliath in every way possible. I thought we had a hand-picked crew that couldn’t be bribed but it looks like I was wrong.”

From the timber-covered hills behind the hangar came the sharp crackle of rifle fire, which was followed by a tense quiet as every man in the great hangar stopped work. When the rifle fire was not repeated, the crews slowly resumed their work and Andy and Bert headed for the hills on the run.

Since the Goliath had been partially financed by a government appropriation and its construction embodied secrets valuable to the war department, a military guard had patrolled the construction site from the day the hangar had been completed and the actual assembly of the dirigible started. On a number of occasions they had apprehended men trying to make their way into Bellevue and without exception the secret service detail at the hangar had found them to be agents of foreign governments. They had been quietly sent to military prisons but in the last few weeks there had been no such arrests and the vigilance of the guards had been relaxed somewhat.

Andy and Bert were half-way up the slope to the guard line when they met Merritt Timms, chief of the secret service unit at Bellevue, coming down the hill.

“Anybody hurt at the hangar?” asked Timms anxiously.

“No,” replied Andy. “We stopped the door in time. What happened on top of the hill?”

“The guard had to stop a man who was trying to get away,” explained Timms. “I’ve been suspecting one of the motor mechanics for some time of sabotage and only ten minutes ago saw him sneak out of the control room door. A second later one of the doors started to open and I knew what he had been up to. I saw you coming to shut off the power and I took after this fellow. He knew he’d have to make a quick get-away and he tried to get past the guard line.”

“Did he refuse to stop?” asked Bert.

“Not only that,” replied the secret service chief, “but he attempted to shoot and the guard fired, but he wasn’t seriously wounded.”

“I can’t feel very sorry for him,” said Andy, “when I think of the half dozen men, on top of the door, he almost killed. If the door had run to the end of its track with the power still on it would have ripped away from its fastenings and perhaps have crushed an end of the hangar.”

“Which is exactly what this chap wanted,” added Timms. “I’ve got a little leather packet here in which he carried some secret papers. We’ll have a look at them.”

The name on the leather folder was that of Cliff Bolton, a common enough American name, but the secret service man and Andy and Bert were in for a surprise when they examined the contents. Documents there showed the true name of the spy to have been Boris Dubra, an agent of the dreaded Rubanian Gerka, whose reputation for unscrupulous methods was known even in Bellevue.

“This puts a new angle on the whole case,” said Timms gravely. “Of course you know that Alex Reikoff, dictator of Rubania, is determined that his air force shall be the most powerful in the world. Until just now we hadn’t discovered a single Rubanian agent trying to get through the lines but it certainly looks as though Reikoff is definitely interested in the Goliath, all of which means we will have to redouble our vigilance.”

“But why should Reikoff have designs against the Goliath?” asked Bert.

“It’s a long story,” replied the secret service chief, “but to boil it down it means that he plans to make Rubania a world power through the development of a great air force. When his planes and dirigibles are the peer of anything else in the world, he will strike out for world power.”

“Which would mean another war,” said Andy quietly.

“Just exactly,” replied Timms, “and when the Goliath is completed and in the air it will dwarf even the great dirigibles Reikoff has turned out at his Blenkko plant in Rubania. Now you understand why the Rubanian secret police, or Gerka as it is better known, is interested in the Goliath. So far we’ve been pretty successful in checking sabotage and this mechanic was the only man they could get into the plant.”

“He was enough,” said Andy, “for had his plan succeeded and the door have crushed an end of the hangar we might have been delayed for months.”

They walked slowly back toward the hangar, discussing further the events which had just taken place and planning for the tightening of the guard lines around the plant.

“As soon as this agent of the Gerka is patched up in the hospital I’ll go over and give him a thorough grilling,” said Timms as they reached the hangar.

“Let me know when you go,” said Andy. “I’d like to see what he has to say.”

“I’ll do that,” promised the secret service agent as Andy and Bert got into the young engineer’s roadster.

When they reached the little building which served as Andy’s office, they found a messenger boy with a telegram for Andy.

“Must be from Dad,” he said as he ripped open the envelope, “and believe me I’ll be glad to have him back here in charge of things.”

Andy scanned the telegram; then he read it again hardly able to believe the words which were typed on the yellow sheet.

“What’s the matter?” asked Bert anxiously.

“Nothing wrong,” grinned Andy, “but it’s news, big news!” With eyes aglow and face reflecting his own enthusiasm he handed the telegram to Bert.

“Rush work with all possible speed,” said the message. “Have just completed plans for Goliath’s first official flight this summer which will take us to North pole for an exchange of mail with the Submarine Neptune, which will be commanded by Gilbert Mathews.”

“My gosh,” exclaimed Bert, “a trip to the North pole. Well, that is news.”

“I’ll say,” replied Andy. “Watch us make time from now on for there won’t be any more accidents with this Rubanian secret agent out of the way.”