Gale stepped silently behind a tree and listened. Her heart was thumping heavily. It sounded like thunder in her own ears. The voices were mere whispers now; only occasionally could she catch the words uttered. She puzzled over the snatches of conversation that drifted back to her.

“Alone—motor in the black plane—so he won’t be able to fly Saturday—now is our chance—worth five thousand to us.” Here there was a lengthy pause before Gale heard: “Let’s go!”

The last sent her sprinting back the way she had come at top speed. Only partly did she understand, but this much was clear: The two men, she supposed there were only two of them, had discovered that Brent was alone at the hangar. They were going back there to do something—anything to keep him from flying in the races on Saturday. She remembered the night when she and Bruce had agreed to take the plans to Stubby. Brent had told them then that there had been a bold attempt on his life once before. It seemed now there was to be another. She covered the distance to the hangar much more swiftly than she had left it. Sheer terror lent wings to her feet.

Brent was sitting outside the hangar where she had left him. He stood up slowly when she came into sight.

“Gale!” he said incredibly, “what is wrong? Has anything happened?”

Gaspingly she told him of the two men she had overheard. He drew her into the hangar while he thought quickly of what to do.

“You must get away,” she said.

“And leave my planes?” he demanded. “I won’t do it. But you must go—now!”

“Can’t you telephone for help?”

He snapped his fingers. “Of course, I forgot.” He drew her with him into the little office. He picked up the receiver and jiggled the hook.

“Hello—Hello—Central!” He slammed it down. “Wires must be cut.”

“Come,” he added a moment later, “you must get out of here.”

They went back to the hangar but discovered it was too late. Someone was tampering with the lock on the door. Brent made sure the inside bolt was secure and drew her back to the office. He crossed to the window.

“Out you go. Back to town for help.”

“Look!” Gale cried.

Even as she spoke a brick was hurled through the window, narrowly missing Brent, and the head and shoulders of a man appeared. He had a revolver in his hand and as he pointed it Brent whisked Gale back into the hangar and the office door shut behind him. He turned the key and hurried her across to the black and silver plane.

“Get in!” he commanded, boosting her up to the pilot’s seat. “Keep your head down!”

“But——” she began.

“Keep quiet!” he cautioned. “You stay here no matter what happens. They won’t see you.”

She said no more but snuggled down, her head just below the edge of the seat. But the blackness and silence was more terrifying than the real danger. Cautiously she raised her head. She wished she knew where Brent was. What was he doing? What were those men doing? The man at the door must have given up his work at the door for she could no longer hear the queer scratching noise.

Rapidly she made a calculation as to the time. Did Bruce and Stubby have enough time to get to the island and start back with the other motor? They had been gone quite a long time, but they had had a lot of work to do. She had no idea when they would be back.

“Brent!” she called in a cautious whisper.

“Here!” he answered at her side. He had been standing beside the plane but in the darkness she could not see him.

“Where are they?” she asked.

“In the office,” he replied.

“Are your plans in there?” she wanted to know.

“No. They are here in the plane.”

“Couldn’t we make a dash for it out the hangar door if they are in the office?”

“We could,” he said significantly, “but we have no idea how many more are on the outside. We better sit tight and wait.”

“But the suspense is terrible,” she declared. “Do you suppose Bruce and Stubby are on their way back?”

“They are our only hope,” he said quietly. “Hush! Here they come! Head down and quiet!”

He stepped away from the plane into the blackness as a rending crash sent the office door flying open. For an instant two shadows were silhouetted against the light behind them and then they melted into the darkness of the hangar. But suddenly a round circle of light appeared and moved quickly over the planes and the hangar. One of the men had a searchlight. Quickly Gale ducked her head as the circle of light traveled over the black plane. Vainly she waited for the shout that must come when they discovered Brent. But the cry did not come. Only silence. Where could Brent be? What was he doing?

“He got away!” a voice said.

“But the black plane is here. That is all we really want anyway,” the other voice agreed.

Gale’s heart beat alarmingly. She was in the black plane! The men’s footsteps sounded on the cement floor. They were coming toward her plane. She gripped the sides of the cockpit and wondered if she should sit quietly or announce her presence with a scream. But there was no need for either. A sudden sound and clank of metal. One of the men groaned and fell to the floor. Brent with uncanny precision had thrown a monkey wrench at a point slightly above the circle of light from a flashlight. It had gone home to its mark. In an instant another spot of light had fastened on him and the intruder’s deadly revolver was aimed directly at Brent. But the pilot did not wait for the shot to come. He launched himself forward and both Brent and the man rolled on the floor.

Gale exposed herself now. How in the world could she keep hidden? She climbed over the side of the plane and dropped to the floor. She moved slowly, carefully toward the wall. If only she could find the light switch! The sounds of the two men on the floor sent nervous chills through her. They were thrashing about dangerously near to her when her fingers found the switch. Light disclosed the intruder astride Brent and pounding away viciously with his fists but Brent managed to throw him off. At the same time the other man showed signs of life. Gale silently stepped behind him and picked up the revolver he had dropped. As the man gripped the monkey wrench which had hit him and advanced on Brent, Gale cried:

“No you don’t. Stand still!”

The man halted in surprise.

“Brent——” Gale called. “I have this one’s gun. I——”

The sound of a motor outside! Voices! Help at last! There was a heavy tattoo on the door and Bruce’s voice.

“Gale—Mr. Stockton!”

Cautiously Gale backed to the door to unlock it as Brent hauled his victim to a standing position by a heavy hand on the man’s collar.

“Open the door, Gale, then we will see what this is all about.”

But the second that Gale relaxed her attention from the man before her to unlock the door was their undoing. The door opened and at the same time the two intruders made a simultaneous dash for the open. The ones outside were too taken aback with surprise to stop them, and by the time Brent and Gale had called a warning the men were dashing toward the road, Bruce and David in hot pursuit. But it was no use. The moment’s start was all the men needed.

“Talk about excitement——” Gale sighed when Bruce and David had returned. “I’ve had all I want for one night.”

“I’ll take you home,” Bruce said immediately.

“I am going to sleep here tonight,” Brent said. “I shall stay here until after the races. Good night, Gale.”

Gale went off with Bruce and on their journey home told him of all that had happened that night at the hangar—that is, all but her talk with Brent. That was for no one but herself!