"Was this a conspiracy?" demanded Tom.

The two captives looked at one another, sitting bound on the floor of the shop, their backs against some boxes.

"I guess it's all up, and we might as well make a clean breast of it,"

admitted Kurdy.

"Perhaps it would be better," said Tom quietly. "Eradicate," he went on, to the colored man, "go to the house and tell Mrs. Baggert that everything is all right and no one hurt."

"No one hurt, Ma.s.sa Tom? What about dem dere fellers?" and the colored man pointed to the captives.

"Well, they're not hurt much," and Tom permitted himself a little smile. "I don't want my father to worry. Tell him everything is all right."

"All right, Ma.s.sa Tom. I'se gwine right off. I'se got t' look after mah mule, Boomerang, too. I'se gwine," and he shuffled away.

"Who else besides Feldman got away?" asked Tom, looking alternately at the prisoners.

They hesitated a moment about answering.

"We might as well give up, I tell you," spoke Kurdy to Ransom.

"All right, go ahead, we'll have to take our medicine. I might have known it would turn out this way--going in for this sort of thing. It's the first bit of crooked business I ever tried," the man said earnestly, "and it will be the last--believe me!"

"Who was the fourth man?" Tom repeated.

"Harrison," answered Kurdy, naming one of the most efficient of the new machinists Tom had hired during the rush.

"Harrison, who has been working on the motor?" cried the young inventor.

"Yes," said Ransom.

"I'm sorry to learn that," Tom went on in a low voice. "He was an expert in his line. But what was your object, anyhow, in attacking Koku?"

"We didn't intend to attack him," explained Ransom, "but he came in when we were at work, and as he went for us we tried to stand him off.

Then your colored man heard the racket, and--well, I guess you know the rest."

"But I don't understand why you came into this shed at night," went on Tom. "No one is allowed in here. You had no right, and Koku knew that.

What did you want?"

"Look here!" exclaimed Kurdy, "I said we'd make a clean breast of it, and we will. We're only a couple of tools, and we were foolish ever to go in with those fellows; or rather, in with that Frenchman, who promised us big money if we succeeded."

"Succeeded in what?" demanded the young inventor.

"In damaging your new aerial warship, or in getting certain parts of it so he could take them away with him."

Tom gave a surprised whistle.

"A frenchman!" he exclaimed. "Is he one of the--?"

"Yes, he's one of the foreign spies," interrupted Ransom. "You'd find it out, anyhow, if we didn't tell you. They are after you, Tom Swift, and after your machines. They had vowed to get them by fair means or foul, for some of the European governments are desperate."

"But we were only tools in their hands. So were Feldman and Harrison, but they knew more about the details. We were only helping them."

"Then we must try to capture them," decided Tom. "Ned, see if the chase had any results. I'll look after these chaps--Koku and I."

"Oh, we give in," admitted Kurdy. "We know when we've had enough," and he rubbed his head gently where the giant had banged it against that of his fellow-conspirator.

"Do you mean that you four came into this shop, at midnight, to damage the Mars?" asked Tom.

"That's about it, Mr. Swift," replied Kurdy rather shamefacedly. "We were to damage it beyond repair, set fire to the whole place, if need be, and, at the same time, take away certain vital parts.

"Harrison, Feldman, Ransom and I came in, thinking the coast was clear.

But Koku must have seen us enter, or he suspected we were here, for he came in after us, and the fight began. We couldn't stop him, and he did for us. I'm rather glad of it, too, for I never liked the work. It was only that they tempted me with a promise of big money."

"Who tempted you?" demanded Tom.

"That Frenchman--La Foy, he calls himself, and some other foreigners in your shops."

"Are there foreigners here?" cried Tom.

"Bless my chest protector!" cried Mr. Damon, who had come in and had been a silent listener to this. "Can it be possible?"

"That's the case," went on Kurdy. "A lot of the new men you took on are foreign spies from different European nations. They are trying to learn all they can about your plans, Mr. Swift!"

"Are they friendly among themselves?" asked Tom.

"No; each one is trying to get ahead of the other. So far the Frenchman seems to have had the best of it. But to-night his plan failed."

"Tell me more about it," urged Tom.

"That's about all we know," spoke Ransom. "We were only hired to do the rough work. Those higher up didn't appear. Feldman was only a step above us."

"Then my suspicions of him were justified," thought Tom. "He evidently met La Foy in the woods to make plans. But Koku and Eradicate spoiled them."

The two captives seemed willing enough to make a confession, but they did not know much. As they said, they were merely tools, acting for others. And events had happened just as they had said.

The four conspirators had managed, by means of a false key, and by disconnecting the burglar alarm, to enter the airship shed. They were about to proceed with their work of destruction when Koku came on the scene.

The giant's appearance was due to accident. He acted as a sort of night watchman, making a tour of the buildings, but he entered the shed where the Mars was because, that day, he had left his knife in there, and wanted to get it. Only for that he would not have gone in. When he entered he surprised the four men.

Of course he attacked them at once, and they sprang at him. Then ensued a terrific fight. Eradicate, arising to doctor his mule, as he had said, heard the noise, and saw what was going on. He gave the alarm.

"Well, Ned, any luck?" asked Tom, as his chum came in.

"No, they got away, Tom. I had a lot of your men out helping me search the grounds, but it wasn't of much use."

"Particularly if you depended on some of my men," said Tom bitterly.

"What do you mean?"