"If you let him get away, you're out of a job, remember."

The cook followed out the programme directed by Duske to the minutest detail. Andy had no opportunity to free himself-he was watched so closely. He decided that the effort would be futile. Until midnight he lay wide awake, nervous and worried. Then he made up his mind that it did no good to fret, and got some sleep.

He was given his breakfast about six o'clock in the morning. Then he was tied up again and left to himself. He lay on the mattress so that when the wind blew the canvas lifted and he could look out. He was faced away from the direction of the aviation field, however, and twenty feet away the fence stared him blankly in the face.

From sounds near by and in the distance during the next two hours, Andy could figure out just what was going on about him. The _Moon Bird_ was carried from its aerodrome and taken to the aviation field. The old cook seemed to be left in possession of the camp. He looked in on Andy every so often. The rest of the time he was busy in the larger tent or outside of it with his cooking utensils.

Poor Andy was in sore straits of despair. He had a vivid imagination, and could fancy all that was shut out from his view by captivity. He heard a distant town bell strike nine o'clock.

"In an hour the airships will be off," soliloquized the captive mournfully, "and I won't be there."

Andy pictured in his mind all that was going on at the aviation field.

He could fancy the airships ranging in place for the start. He could imagine the animation and excitement permeating the groups of spectators. He shut his eyes and tried to forget it all, so keen was his disappointment.

He heard the band strike up a gay tune. Then a gun was fired. Andy almost shed tears. In twenty minutes the starting signal was due.

"They'll have a head wind," he ruminated, as the breeze lifted the canvas at the side of the mattress upon which he lay. "It will be light, though, and won't hinder much;" and then he thrilled, as he fancied himself seated in the operator's stand of the splendid _Racing Star_, awaiting the final word, "Go!"

Andy stared blankly at the fence of the enclosure of the Duske camp. A section of it had been broken down, and the gate left open in removing the airship. Of a sudden he stared eagerly. Some one had come into the enclosure.

The intruder was evidently some casual sight-seer, a boy. His hands were in his pockets, and he strolled about as if curiously inspecting everything that came under his notice. He cast a careless glance at the tent, and was proceeding on his way towards the main aviation field, when Andy gave a great start.

"Silas-Silas Pierce!" he shouted, ignoring discovery by the cook.

Andy's heart was thumping like a trip-hammer. It seemed as if on the verge of the blackest despair a bright star of hope had risen on the horizon. He had recognized the intruder with surprise, but with gladness as well.

It was his companion of the goose trip, the son of Mr. Pierce-the farmer Silas-whom Andy had last seen at the Collins place, the farm he had visited the day previous. Silas wore a brand-new suit of clothes. He suggested the typical country boy, with some loose cash in his pocket, enjoying a brief holiday to the utmost.

"Hey!" exclaimed Silas, with a startled jump, his eyes goggling all about, and unable to trace the source of the challenge.

Andy uttered a groan. At the moment the breeze let down, and the canvas dropped, shutting him in and Silas out. Then a puff of wind came and lifted the flap again.

"Here, here, Silas!" called out Andy in tones of strained suspense.

"Quick-help!"

"I vum!" gasped the farmer boy, staring blankly at what he saw of Andy.

"Who is it? And-I say, you're dad's great friend, the Nelson boy!"

Silas had advanced, and took in the situation, and recognized Andy slowly.

"Lift up the canvas; come in here," directed Andy in a more cautious tone of voice. "You remember me, don't you?"

"Guess I do; but what in the world of wonder is the matter with you?"

"Don't talk so loud," pleaded Andy anxiously, fearing the arrival of the cook at any moment. "Some bad men have tied me up. Have you got a knife?"

"Yes; and a brand-new one. Won it in a funny game where you throw rings.

See there," and with great pride Silas produced and opened a gaudily-handled jack-knife.

"Oh, thank you, Silas; I'll never forget this."

"Hold on! Say! Thunder! Is he crazy? Stop! Stop!"

In profound excitement, Silas Pierce regarded Andy. The minute he had cut the bonds of the young aviator, Andy had bounded to his feet as if set on springs. Afar from the aviation field there boomed out the second, the get-ready gun.

"Ten minutes!" gasped Andy, on fire with resolve. "I've got to make it."

He swept aside the canvas, headed in the direction of the main camp. Hot on his heels came his amazed rescuer, now a wondering pursuer. Andy ran at the fence, gave a spring, and cleared its top in a graceful leap.

Silas, more clumsy, ran at two loose boards, and by sheer force of his might and strength, sent them out of place and put after Andy.

"Nelson!" he bawled. "What's the matter? n.o.body's following you.

Crickey, but you're a sprinter!"

"I'll see you later-Parks' camp-in a hurry."

In a hurry, indeed, was Andy. He was running against time. As a turn past some tents brought him in full sight of the open field, he was a lone heroic figure-heart, brain and body strained to reach the dainty, natty _Racing Star_, just being wheeled in place for flight.

There were seven airships entered for the race. These were now stationed a distance of several hundred yards apart, ready to start. The spectators were held back from the dead line by ropes stretched from post to post, but Andy was coming across the field from its inside edge.

Silas Pierce was putting after him, puzzled and excited, breathless, and far to the rear. Their unconventional arrival attracted no attention, for those in charge of the airships were engrossed in seeing that everything was right for the start.

The _Racing Star_ was being pushed forward to its starting position. All the others were in place. In a swift glance, Andy made out the _Moon Bird_, and recognized Duske seated amidships.

Near the _Racing Star_ was Mr. Parks, directing affairs, and Scipio was standing near by. At one side were Mr. Morse and Tsilsuma, deeply interested in the manoeuvres going on.

"It's Tyrrell!" panted Andy, and he redoubled his speed as he made out the treacherous ally of Duske. Tyrrell was arrayed in leather jacket and gloves, keeping pace with the _Racing Star_ as it moved along. As the airship came to a halt on the starting line, Andy saw him move forward to take his seat amidships.

It was then that Andy ma.s.sed all his strength of being, accompanied by animated gesticulations, as he shouted out:

"Stop that man!"

CHAPTER XXII-"GO!"

"Andy!" shouted John Parks in a transport of amazement.

"It's me," panted Andy, running up to his employer and pointing at Tyrrell. "Mr. Parks, stop that man. He's a traitor; he's a villain!"

Tyrrell had heard and seen Andy. He gave a great start. Then he made a move as if to hasten aboard the airship and get out of his way. Mr.

Morse and the j.a.panese hastened forward. The men guiding the aeroplane stared hard at the newcomer.

"Andy, what do you mean?" demanded Mr. Parks, lost in wonderment.

"Just what I say. Don't let him get aboard."

"Hold on, Tyrrell," ordered the aeronaut.