CHAPTER XXIV.

THE SKY SLAYER.

After the first greetings were over, Jack plunged into an explanation of their presence in Belgium in such stormy times. M. La Farge looked grave, but promised to do what he could through diplomatic and other sources to locate Tom Jukes.

"If, as you say, he has been traveling in state in a large auto, he ought to be easy to locate," he assured them. "I will let you know what I have been able to discover to-morrow morning. Every auto entering the country is registered and its occupants kept track of. Rest assured I shall do my best for the two young friends to whom I can never be sufficiently grateful."

Jack thanked him warmly for them both, and explained that while in London they had communicated with the American consuls in Paris and Berlin, but that nothing had been heard at either place of Tom Jukes being among the refugees beseiging the American representatives.

"Possibly I shall have better success. At least, we must hope so," said M. La Farge. "Much of the telegraph system is still intact, fortunately. At least rest on my promise that I will do all I can."

As they had already visited the American consulate in Antwerp, where they had obtained no news, the two boys found themselves without anything to do but kill time as best they could till the next day. As they had spent much of their time on the Dutch steamer in sleep, they did not feel like turning in early and so, at Jack's suggestion, they visited a theatre. But it was a gloomy manner of spending the evening, as it transpired. The inhabitants of Antwerp were more interested in the bulletin boards announcing the inroads of the German troops than in entertainments. There was an air of anxiety and depression abroad that could not help but be contagious, and oppressed by the general atmosphere, the boys decided before the end of the performance to return to their hotel.

But Jack could not sleep. He lay awake tossing and turning for an hour or more. In the street he could hear the regular step and quick challenge of sentries. Occasionally, far off, came the sound of bugle calls.

All at once he became aware of another sound. It was one that was strange to him. He could liken it to nothing but the droning buzz of a giant bumblebee. It was at first faint; hardly audible in fact, except to strained ears, but it rapidly grew in volume, filling the whole air with the steady vibrating buzz.

The sound irritated Jack, sleepless as he was.

"It sounds for all the world as if there was a big buzz saw or a threshing machine at work," he mused. "Where on earth does the racket come from?"

He lay awake listening for a few moments longer. Then he got out of bed and tiptoed across the room where Bill lay snoring violently.

The lad looked out of the window. The street and a public square lay far below him. Only a few lights shone on the thoroughfare. It appeared deserted but for the sentries marching up and down unceasingly.

"Nothing there," said the boy to himself. "I guess I'll turn in again."

The buzzing sound had grown fainter now. It was hardly audible in fact. But for some reason it lingered in Jack's mind. It was like half a dozen things he could think of and yet he could not recall ever having heard that precise sound before.

At last he dozed off, and then sank into a dream in which it seemed to him that he was somewhere far out in the country lying under a shady tree contentedly chewing on a bit of grass and gazing up through the leafy branches at the bright sky. But suddenly everything clouded over. The landscape grew dark and sinister, and the leaves of the tree above him began to toss and sway in a harsh wind.

In his dream, Jack arose and standing up looked about him. It appeared to him as if he was gazing down from a height over an immense battlefield. He could see the dust and smoke as cannon were wheeled into position and then the flashes of flame and the belching of fire from the rifle pits. Men were mowed down like ripe grain in long windrows.

It was horrible but fascinating.

Then, all at once, came again that strange buzzing sound. But now it seemed to have in it a menacing note. It was like a terrible voice. The boy shuddered as he heard it, harsh and inexorable, filling the air, which seemed to vibrate to the steady humming.

It grew sharper and louder. Above all, the noise of the dream cannon and rifles, the boy could hear it. He awakened with a start, his heart beating rather wildly.

"That was a kind of a nightmare," he said to himself. "Glad I woke up. I guess--what's that?"

Again that humming sound filled the air as if a pulsing chord, strung at high tension, had been twanged.

"It's outside!" exclaimed Jack, for the second time going to the window.

"It's in the air!" he cried an instant later.

He turned his face upward. High above the city, against the stars, he could trace the outline of a gigantic cigar-shaped body. It was moving slowly far above him.

"An airship!" gasped the boy, and then the next instant:

"A Zeppelin!"

Something seemed to launch itself from the dark body of the immense aircraft and streak downward like a falling star. The next moment, from a part of the city some distance off, there was a brilliant flash of flame, and then an appalling report that shook the earth. But Jack had no eyes for this at the moment. His gaze was fixed on the Zeppelin.

Having dealt destruction in one part of the city it was now making directly toward the hotel!

The boy watched it with a horrible fascination that held him speechless.

The death-dealing craft was destined to pass directly above the building that sheltered them and how many others. Craning his neck, Jack watched its flight above the sleeping city. Dark as death itself and, with no indication of its presence but the drone of its engines, the sky monster moved majestically toward him. It was then that Jack suddenly found his tongue as the death in the air approached till it was almost above his staring eyes.

"Bill," he yelled, "Bill, wake up!"

He shook his chum's shoulder violently.

"Whazzermarrer?" inquired Bill sleepily.

"Get up for your life. Fling on any old clothes. Let's get out of here quick."

"What's up?" demanded Bill, wide awake now, and hastily pulling on some clothes, for he knew Jack would not have aroused him needlessly.

"It's a Zeppelin, a giant German airship. She's blown up a piece some blocks away and now she's headed over here."

At almost the same instant, a roar of artillery burst forth. The defenses of Antwerp had awakened and were concentrating their fire on the death-dealing monster of the sky. But as the first reports ripped the silence of the night, there came another and a mightier report. The hotel rocked to its foundations. A shower of plaster and debris crashed into the boys' room, half burying them.

The sky slayer had struck again!