CHAPTER XIII The Battle in the Clouds

For three hours they had raced along thus, and then the first trouble developed with one of the motors. It blew out a spark plug.

Now, while this is not a difficult repair for an expert motor mechanic, nevertheless it necessitated another costly delay, and when they again got under way with full power it was with the determination that nothing short of a catastrophe should again interfere with their passage.

"As it stands now," said Jack, "if we go on without interruption we're likely to hit the Irish coast in the dead of night. Even at that, though, I'll be solemn glad to set foot on land again."

"So say we all of us; so say we all of us," Andy chimed, in the words and tune of a well-known song.

Fifteen minutes later they sighted the first ship they had seen since leaving Halifax. Up to the present this hadn't seemed strange to them; as a matter of fact they hadn't been thinking of surface vessels; but now that they gave it consideration they realized it was because they had been carried off their course by the storm, or couldn't see the lights of one because their own attention was given entirely to trying to save their own craft.

"Looks pretty badly battered, at that," said Don, opening the fusilage and gazing downward. "Fred, let me have the glasses, will you?"

He took the powerful glasses and for a moment gazed downward. Then he began to laugh. "They're sizing us up the same way," he chuckled. "Guess we do look strange to them, away out here."

In another moment something happened which made them all sit up and take notice. There was a puff of smoke, a faint report, and a bullet whizzed through the air not more than fifteen yards away from them.

"Holy smoke!" shouted Andy. "It's all clear now. That's the ship that Braizewell's wireless was talking to. They take us for air pirates with stolen government papers."

In another instant they shot upward at amazing speed, in a zigzag course.

"Haven't got the time or inclination to argue it out with them," said Jack, "although if they don't keep that pop gun still we'll turn our nose down and let 'em have a volley, just by way of a return salute. They can't maneuver out of the way as we can."

But by now they not only were out of range of the gun on the ship, but also almost out of sight of the vessel's crew.

"Ta, ta, Jenny," Andy waved over the side, in mock misery at parting company. "See you later where the grass is greener."

At an altitude of nearly two miles they were skimming through the air at something more than a hundred miles an hour when Fred again uttered an exclamation of surprise.

"What now?" Don demanded.

"Wait!"

Again the engines were shut down to permit Fred to hear more clearly.

"The other plane and the ship are talking again, but I can't make it out," he explained. "It's all garbled, and I can only get a word here and there. Sounds like some sort of a code. By Jingo! It is! They're evidently talking to some other ship, and one friendly to them, at that. Conversation don't make sense at all."

He listened intently for a few moments and then gave a grunt of disgust. "They've stopped," he said. "Nothing more doing."

However, this was to be Fred's busy day, and only another short interval elapsed when something came to his ears that caused him to straighten up instantly to the closest attention.

Don, sitting near him and watching him, saw his eyes widen perceptibly, as though he was incredulous of what he heard. For several seconds he sat in the same position, not a muscle of his tense countenance changing, and then unconsciously his right hand went out toward his sending key. It rested there, however, and he sat immovable, making no effort to throw on the switch to connect the power necessary to send out a radio.

"Here," he said at last, clapping the earpieces onto the head of the surprised Don. "You don't know the radio code, but just raise and lower your hand with the length of each sound you hear. I don't know whether I'm hearing straight or have gone looney."

It was a moment before Don could distinguish anything, for he was not trained to the sound of the radio; but after an interval he suddenly raised his hand, then dropped it again, raised it and dropped it, at varying intervals in time with the short and long sounds he heard, and resembling in his actions some sort of an automatic contrivance more than a human being.

For he could neither understand nor interpret what he was, however, merely verifying to the astonished Fred.

"Do you know what that is?" the latter asked of the other two, who now were as interested as the mystified Don was.

"What?" asked Jack.

Before answering, Fred again put the receivers over his own ears. The call still was being repeated.

"Our call," he informed them brusquely. "R-S-7—and there's no doubt that it's being sent out by that other plane. Shall I answer?"

"Not under any circumstance," Jack commanded, for the first time really exerting his prerogative as captain of the crew.

"They're saying something," interjected Fred, grabbing pencil and pad and beginning to write rapidly.

A moment later he laid aside the receivers and picked up the paper to read aloud. "Listen to this," he said. "Here's what I caught: 'R-S-7. If you can catch this, reply immediately. Mistake been made. Return at once.'"

"Who signs it?" Jack asked.

"No signature at all; they just kept repeating that message," said Fred.

"Well, let 'em keep on repeating it," Jack snapped out. "Poor idiots! They might know that scheme wouldn't work. They just want to get a line on where we are. If Bronson or anybody in authority wanted to reach us it would come in our code. It shows, though, that those fellows are determined to reach us for a mix-up if they can."

"Yes," said Don, picking up the marine glasses and gazing intently to the westward behind them, "and it looks as though they were going to come mighty near doing it, too. Great Scott, Jack! take those glasses and look at that burst of speed."

He handed the glasses to Big Jack, while the others also turned their gaze to where the naked eye could just discern a slowly enlarging speck over the western horizon.

For a full minute Jack remained with the glasses to his eyes. Then he turned to look at his own air-speed indicator.

"We're doing a hundred and fifteen," he announced. "We'll put her up to a hundred and twenty-five, and without the aid of a favorable wind that's about the best we can do. Figuring the way they've been crawling up on us, even with us going at a hundred and fifteen, they must be doing something like a hundred and thirty-five at least."

He pondered for a moment and turned another backward glance. "Well," he ejaculated at last. "I guess those papers are more important than even we guessed. Those fellows aren't coming through on petrol: they're using a mixture of at least twenty-five per cent ether!"

Twenty minutes elapsed and it developed into what well might have been a life-and-death race, with the pursuing plane steadily cutting down the intervening distance—steadily gaining on the one that already was plowing through the air at the rate of a hundred and twenty-seven miles an hour according to the air-speed indicator, and probably not less than a hundred and twenty miles an hour ground speed.

Another half hour and the pursuing machine had sufficiently reduced the distance to let go the first volley of shots from her machine gun.

"Ah," exclaimed Jack, "prepared for action, eh? Well, maybe we can give them a little surprise. I don't think they know we're armed."

He started climbing, and so suddenly and at such an acute angle that the pilot of the other plane could not see the intended maneuver soon enough to parallel the course.

"If it's really a fight they want, I reckon the time has arrived when we'll have to stop and give it to them," he breathed again through clenched teeth. He and Andy now were working together like a pair of Siamese twins. The dual motors were turning out a new specimen of power, as though by some human intelligence they, too, realized that the moment of supreme test had come.

"Don," Jack shouted, "you'll have to work that machine gun. Andy is needed here in the cock-pit."