When Andy taxied the Ace across the field at Bellevue and up to the concrete apron, he found Bert waiting for him. The radio operator was nearly bursting with curiosity to learn what Andy and the secret service chief had found at Alden.

“Control yourself, Bert, control yourself,” grinned Andy as he hoisted himself out of the cockpit and slid to the ground.

“You can’t blame me for being curious,” replied Bert, “when I’ve been marooned here for the last twelve hours while you’ve been chasing excitement all over southeastern Kentucky.”

“That’s just it,” said Andy. “We were only chasing. We didn’t find a thing to give us thrill.”

“No trace of the mysterious flyer?” asked Bert.

“Nary a sign,” replied Andy. “We found where his plane had attempted to bore its way through the side of a hill but he had evidently dropped out some time before in his chute. He’s probably securely hidden waiting for a chance to bring about the destruction of the Goliath.”

“That won’t be an easy thing to accomplish,” said Bert. “The guard lines have been tightened so a bird can hardly fly over them without being stopped. The army planes came in before noon and any flyer who violates the department of commerce regulations by flying over this air reservation will find a handful of slugs singing through his wings.”

Andy nodded grimly as he looked at the group of army machines in front of a hangar further down the field.

“We’re ready for business now,” he said. “I’d like to meet the officer in command.”

“He’s a fine fellow,” enthused Bert. “Not much older than we are. His name is Lieutenant Jim Crummit of Selfridge Field, Mich. He’s one of the ace pursuit flyers of the air force and the rest of the fellows with him are not far behind when it comes to handling a plane with a machine gun on the business end of it. They’re just itching for something to happen.”

“I’m afraid they’ll be disappointed,” said Merritt Timms, who had just emerged from the cockpit, having experienced some trouble in unfastening his safety belt. “They would have had plenty of fun if they had been here yesterday but from now on the game will be played on the ground or aboard the Goliath when it goes on its trial flights.”

“Here comes Lieutenant Crummit now,” said Bert, stepping forward to greet the tall young officer in command of the detachment from Selfridge Field.

Bert introduced the lieutenant to Andy and the secret service agent, who cordially welcomed the army man to Bellevue.

“Our field is a little bumpy but we’ll try and make up in hospitality what we lack in air accommodations,” said Andy.

“The field is O.K.,” smiled Lieutenant Crummit. “A couple of the boys came in too fast and bounced a little high but they’ll soon get over that. We’re all glad to be here where we can watch the completion of the Goliath.”

“I understand several ships will be detailed to accompany us on all trial flights,” said Andy.

“Those are the orders direct from Washington,” said the lieutenant. “Now, somebody tell me what all the fuss is about?”

They walked over to the office where Andy and the secret service chief explained in detail every event of the preceding twenty-four hours.

“That does look serious,” said Lieutenant Crummit, “especially since you have an admission from the agent of the Gerka you caught here that an attempt was to be made to destroy the Goliath. At least you can feel reasonably safe from an air attack. Anti-aircraft equipment with night lights will be in tonight and the unit also carries special microphones for the detection of planes in flight. Any craft approaching here will be known while it is miles away and we can give it a warm reception.”

Assignment of the army flyers to quarters had been held up pending Andy’s return and he arranged for them to have accommodations at the hotel, six of the construction foremen agreeing to give up their double rooms and move over to the company houses on the reservation proper.

It was late afternoon before Andy was alone in his office with an opportunity to go over the day’s mail There were several important looking letters on top but he shuffled through the stack until he came to one in his father’s familiar writing. He slit it open and read it eagerly. It was with a real feeling of relief that he learned his father and Captain Harkins would return late the next day, coming in on a special National Airways plane. His father wrote that final arrangements had been finished for all of the delicate apparatus which was to go into the control room of the Goliath and that, unless there were unforeseen developments, everything was now lined up so that construction would be completed ahead of schedule.

The afternoon freight train brought the anti-aircraft unit, with its searchlights, field pieces and other equipment. The twenty-five men of this company were housed in company quarters, which had been vacated only the week before by a crew which had finished its work.

Before nightfall Bellevue had been turned into a truly military camp with its strict guard around the grounds of the National Airways plant, the army planes ready to take the air at any time of day or night, and the great searchlights, crouching under their shrouds of canvas, eager to send their searing blue-white beams tracing through the night sky.

“When a fellow looks over the field now,” said Bert as they walked to the hotel for supper, “he realizes just how valuable the Goliath is to Uncle Sam.”

“We’ve got the jump on them now,” said Andy. “Dubra failed in his attempt to damage the hangar and is now in our hands. That means the ‘inside man’ on whom Reikoff had counted for cooperation with this newcomer from Rubania is out of the picture and our guard lines have been tightened until it is almost physically impossible for anyone to get through. But even with all those precautions, we’ll continue to keep our eyes and ears open.”

Supper that night was a jolly affair, with introductions of Lieutenant Crummit and his companions to the engineers and foremen in charge of the building of the Goliath. The army flyers were keenly interested in the construction of the great dirigible and Andy enjoyed Lieutenant Crummit’s practical inquiries on the stability of the big gas bag, what it was expected to do when in the air and its availability for war-time use.

“We know in a general way,” he said, “but nothing very definite has appeared on the actual capability of the craft.”

Andy had an enthusiastic second in Bert and they went over a complete outline of the Goliath and its range, both in peace and war times, for the army men. By the time they were through, supper was over and the group broke up in twos and threes and straggled into the lobby of the old-fashioned hotel. The air was chilly and a great fire had been built in the fireplace. Lights were low and there was a general spirit of comradeship in the room. The radio had ceased its accustomed blare and a really excellent orchestra, devoid of the usual advertising propaganda, was playing familiar airs.

Someone started humming and in another minute the room was filled with lusty voices that took up the refrain. For half an hour they enjoyed the impromptu concert until a messenger boy came in with a telegram for Bert.

The young radio operator looked surprised as he fingered the yellow envelope, turning it over as though half expecting to find the address of the sender on the back.

“Now who under the sun could be telegraphing me?” he asked.

“Better open it and find out,” suggested Andy.

“A most original proposal,” replied Bert tartly. “It’s from Harry Curtis,” he cried as he read the message. “He’s going to the North pole as radio operator for Gilbert Mathews on the submarine Neptune.”

“My gosh,” Bert continued in the same breath. “That means we’ll meet Harry at the North pole sometime this summer.”

“Well, that is a coincidence,” said Andy, who had met Harry Curtis the year before. Bert and Harry had served the department of commerce together and were close friends, a friendship which had not dimmed by their separation. Andy had taken a liking to Harry on their first meeting. Harry had visited at Bellevue during the preceding summer and their friendship had developed rapidly.

“What a thrill we’ll have saying ‘hello’ to each other in the Arctic,” he said.

“But that isn’t all,” added Bert. “It seems that your father and Mathews have agreed to keep in touch with each other by radio so Harry has been ordered here to check up on our radio equipment with me. We’ll arrange for complete synchronization of the sets so that we’ll be able to get through to each other at any time.”

“That sounds like Dad,” said Andy. “He’s always looking ahead and planning for any emergency. It will take careful timing to bring both the Neptune and the Goliath to the pole at the same time. Believe me, Bert, you’re going to have an important job when the Goliath finally sticks her nose into the air and heads north.”

“I’m commencing to realize how really important it is,” said Bert soberly.

“Hey, wait a minute,” he added. “I almost forgot one of the most important parts of this telegram. Harry said he was starting at once for Bellevue.”

“Good,” said Andy. “Where was the message sent from?”

“New York,” replied Bert.

“That means it will be tomorrow afternoon before he arrives,” reasoned Andy as he mentally outlined the train schedules between the metropolis and the isolated Kentucky valley.

The group in the hotel lobby broke up, most of the men going to their rooms to write letters or read while a few gathered around a chess board. Andy had some correspondence to finish and he walked down to his office. Reports for the day showed better than average progress had been made on the Goliath and he wrote these into the permanent record of the construction of the mammoth craft.

For an hour he worked at his desk, catching up on the mail which had come in that morning. All of it was routine with the exception of another short notice from the war department that Herman Blatz, the civilian observer from Friedrichshafen, would arrive at Bellevue the next day. It added that every courtesy of the National Airways plant should be made available to the newcomer.

The note irritated Andy. He was inclined to be suspicious of any newcomer now but he realized that he would have to master that feeling for they were deeply indebted to Doctor Eckener for his many contributions to the advancement of dirigibles. Andy filed the letter from the war department and was about to leave his office and return to the hotel when the blast of a siren cracked the night wide open. It was shrill, penetrating, alarming—the kind of noise that creeps up and down the spine and makes the short hair at the back of the neck stand straight up.

Lights flashed on in the anti-aircraft battery down the field. Hangar doors swung open. Mechanics popped out of beds and into their clothes. Canvas hoods were ripped off the searchlights and the dynamos hummed with energy.

The microphones had picked up the sound of an approaching airplane. Propellers of the army planes spun. Flame whimpered around the exhaust stacks. Ammunition belts were fed into the black, deadly little guns.

Andy ran along the line of fighting planes. They were poised; eager for the word to go. Every other light in Bellevue had been put out. There was only the occasional flicker of the exhaust of one of the waiting planes. He felt out of the picture; the army was in command. He stopped beside Lieutenant Crummit’s plane and the army officer leaned down.

“Room enough in here if you want to pile in and see this shindig,” he shouted.

The invitation was followed by the acceptance in action and Andy vaulted into the cockpit of the speedy fighter. It was lucky they were both slender but even then it was a tight squeeze.

“How do you know when to go?” asked Andy.

“The plane was ten miles away and heading this way when the ‘mike’ picked it up,” replied Lieut. Crummit. He glanced at his wrist watch.

“The searchlights will go on in ten more seconds. We’ll start up the minute they fasten on anything.”

The words were hardly out of his mouth when the night awoke to a blue-white brilliance as the searchlights sent their beams soaring into the sky. Back and forth moved the giant fingers of light, each one covering a certain area. Any plane near the reservation was certain of detection.

There was a cry from Lieutenant Crummit.

“There it is,” he shouted as he gunned the pursuit ship. It seemed to Andy that they jumped straight into the air, so fast was the rise of their craft. Up and up they went, the brilliant light from below pointing an unerring path toward the plane they sought. It was a black biplane, fast and streamlined.

The pilot was twisting and turning to get away from the pursuing beams of light but his task was useless with the army pursuit ships rising from below in an angry swarm.

They were at two thousand feet in no time and level with the craft they sought. Lieutenant Crummit pressed the trigger of his machine gun and a stream of tracer bullets coursed through the night, singing past the machine ahead.

Andy saw the pilot turn a desperate, terror-stricken face in their direction. Someone in the forward cockpit was waving. They drew closer. The plane was giving up. A white handkerchief was being waved by the passenger.

Lieutenant Crummit drew closer and signaled for the black biplane to follow him down. The pilot waggled his wings to indicate that he understood the order and they began the strange descent, Lieutenant Crummit and Andy in the leading plane, then the strange biplane followed by the five other army ships.

The operators of the searchlights changed the direction of their beams, turning them on the field to make it easy for the night landing.

As soon as their own plane had stopped rolling, Andy leaped out and ran toward the black biplane. Lieutenant Crummit was only one stride behind and in his right hand he carried a service automatic.

Andy was astounded to hear a familiar voice from the black plane.

“What kind of a reception is this?” was the demand and he looked up into the face of Harry Curtis, radio operator of the Neptune, whom they had not expected until the following day at the earliest.

“Who is this fellow?” Lieutenant Crummit wanted to know.

Andy explained that Harry had been ordered to Bellevue to plan for the radio communication between the Goliath and Neptune during their Arctic trips and Lieutenant Crummit broke into a broad smile.

“At least we gave you a real army welcome,” he chuckled. “It’s lucky one of the other boys didn’t reach you first, though. This is restricted flying territory and he might not have sent his first burst of tracers alongside just as a warning.”

“I was scared to death,” confessed Harry, who had climbed down from the plane just in time to receive a hearty greeting from Bert. “Believe me I sure scrambled around trying to get a handkerchief out of my pants pocket.”

The civilian pilot of Harry’s plane came in for a severe reprimand from Lieutenant Crummit, who warned him not to repeat the offense again.

Dynamos for the searchlights were turned off, planes wheeled back into the hangars and Bellevue turned on its lights once more. They had had their first night alarm and the army men on the job had proved their ability to handle the emergency.