"So you really do want to buy my silence?"

"I want to make sure that you will not attempt to defeat our plans."

"Nothing doing," Ned replied.

"Wait!" Collins continued. "You haven't heard me out. We'll see that Lyman gets all his money out of the deal, with something besides, and also that you get a quarter of a million dollars for saying nothing."

"Nothing doing!" Ned repeated.

Collins actually gasped with amazement. He had offered bribes before, but had never started out with so large a sum. And he had never been denied!

"Understand the proposition," Collins said, presently, as soon as he could catch his breath, "it is not you we want. We don't care a continental cuss for you. What we want is for you to keep quiet after we find Lyman. It is the Secret Service of the United States we axe afraid of. I'll make it half a million."

"It must be a rich concession," Ned said.

"It is, and Lyman got it for a song, for no one ever supposed that swamp would make good grazing ground."

"I guess Mr. Lyman will earn all he gets out of it," Ned laughed.

"He will never get anything out of it, unless he comes to terms with me," Collins said, impatiently. "We'll find some way to keep him out of Asuncion until after the 31st. It is a long way from here to Paraguay!"

"All the more reason why we should get busy looking for him," Ned said.

"And when we find him?" asked Collins, tentatively.

"I shall take him back to Asuncion."

"Then you'd better not find him," threatened Collins. "If you're going to oppose me, I'll leave it to you to look him up. I'll go back to Asuncion and bring men out here who will see that you never leave the mountains."

"Gee! That's a cheerful proposition!" grinned Jimmie.

Collins, disgusted at his failure to either bribe or frighten the boys, started away, but Jackson laid a heavy hand on his shoulder and swung him around.

"Wait a minute!" he said.

"What do you mean?" demanded Collins.

"You're not going to Asuncion after help," Jackson said. "I have a little score to settle with you myself! You're the man who accused me of running off cattle. Well, you're going to remain right here with me until I go out with you and give you a chance to make that right."

Collins glanced at Ned.

"Is this by your order?" he asked.

Ned shook his head.

"I have no present quarrel with you," he said.

Collins started away again, but Jackson thrust him back, not any too gently.

"If you make a touse," he said, "I'll tie you up. Now," he added, as Collins, almost foaming with rage, threw himself on the ground, "I want you to tell me where you left that tent."

Both Ned and Jimmie sprang to their feet at the mention of the word.

"A tent! Here!"

Collins snarled out some impertinent reply, and Ned asked:

"Did they bring in a tent?"

"You bet they did!" Jackson answered. "This fine-haired duck with the circus parade clothes wasn't going to sleep in no cavern. He was going to have a nice, soft, cool bed under a tent while he was waiting for the Lyman concession to lapse. He was reared a pet--he was!"

The ex-cowboy was so enraged at Collins for the insinuations he had cast upon him that he pushed up to where he lay and would have a.s.saulted him if Ned had not interposed.

"Let him alone," the boy said. "We'll leave the law to make payment in his case. Are you going to tell us where the tent is, Collins?"

he added, turning to the angry captive.

"I guess you can get along without the tent," Collins said. "You won't have to remain here long. I've got men coming in. They may be here at any moment. Officers of the Republic of Paraguay!"

"I shall be glad to meet them!" Ned laughed. "If you'll tell me where the tent is I'll be able to entertain them properly."

"Aw, I can find the tent if it is around here anywhere!" Jimmie broke in.

"What do you want of it?" demanded Collins

"A little tent cloth," Ned smiled, "would make a serviceable machine of the Nelson. We could make new planes in no time. What do you think of the idea?"

"I'm not going to have the tent cut up," shouted Collins.

"I guess yes," Jimmie said, provokingly. "You burned our planes, and you've got to supply material for new ones."

The little fellow darted away as he spoke, working his way over the ledges which separated the two dents on the mountain sides. In a short time Ned heard him calling and saw him looking down from the shelf above the cavern.

"Come on up," the lad cried. "I can see the tent over in the other valley, and there's another automobile coming. What do you think of that? This must be a regular station on the underground railroad between Asuncion and Lymanville!"

Ned lost no time in gaining the ledge. The white body of the tent was in plain sight, just where the men had dropped it out of the machine. The two boys hastened into the depression, seized the canvas in their arms, and started back toward the Nelson. On the shelf again, Ned asked:

"Where did you see a motor car?"

"Over east," was the reply. "There's a tunnel under the range off that way. I take it that a river ran there once, draining this valley."

Presently the machine appeared in the valley from which the Vixen had slipped off into the pit. There were four men in the two seats.

One was the Indian in goggles who had driven the car away, the others were white men. The car could not have gone far, so these men must have been picked up just outside.

The boys carried the canvas down to the Nelson and began the work of making new planes, keeping close watch, but leaving the newcomers to do the calling if there was any to be done. There was plenty of canvas and the tools necessary for the work were found in the Nelson's tool chest. Collins watched the doings angrily.

"These men," he finally said, "are officers. Two from Paraguay and one from Peru. They have warrants for your arrest."

He started to his feet as if to join the others as he spoke, but Jackson saw that he did not get very far.