“I want only my rights, and that for which I paid,” concluded Mr. Jenks.  “Now, I gather that these men haven’t treated you altogether fairly, Bill.”

“Indeed they haven’t.  I helped ’em to the best of my ability, and all I get out of it is to stay out on this lonely side of the mountain, and play ghost.  They owe me money, too, and they won’t pay me, either, though they have lots, for they sold some diamonds lately.”

“Then they are still making diamonds?” asked Mr. Jenks, eagerly.  “Have you seen them?  Do you know the secret?”

“No, I don’t know it, for they won’t let me in on it.  I’m always sent out of the cave just before they make the gems.  But I know they’ve made some lately, and have sold ’em.  I want my share.”

“Look here!” exclaimed Mr. Jenks, quickly, wishing to strike while the iron was hot.  “I’ll make you a proposition.  Show us how to get into that cave, unknown to the diamond makers, and I’ll pay you twice what they agreed to.  Is it a bargain?”

Bill Renshaw considered a moment.  Then he thrust out his hand, clasped that of Mr. Jenks, and exclaimed: 

“It is.  I’ll take you into the cave by an entrance that’s seldom used.  There are four ways to get in.  The one where the two men drove you back is the rear one.  The front one is on the other side of the mountain, but it’s so well concealed that you’d never find it.  But I can take you to one where you can get in, and those fellows will never know it.  And, what’s more, I’ll help you if it comes to a fight!”

“Good!” exclaimed Mr. Jenks.  “I think we’ll discover the secret of the diamond makers this time,” and he went to tell the others of the success of his talk.  Bill Renshaw had been converted from an enemy into a friend, and the former phantom was now ready to lead Tom and the others into the secret cave.

“We’ll start in the morning,” decided Mr. Jenks, who, after many disappointments, at last saw success ahead of him.

CHAPTER XIX—­IN THE SECRET CAVE

Tom Swift was up at break of day, and the others were not far behind him.

“Now for the secret cave!” cried the young inventor as he gazed up the mountain, in the interior of which the mysterious band of men were making the diamonds.

“Have you made any plans, Bill?” asked Mr. Jenks of the former phantom, who had cast his lot in with the adventurers.  “What will be the best course for us to follow?”

“You just leave it to me, Mr. Jenks,” was the answer.  “I’ll get you into the cave, and those fellows, who, I believe, are trying to do me out of my rights, as they did you out of yours, will never know a thing about it.”

“Bless my finger-nails!” cried Mr. Damon.  “That will be great!” We can get in the cave, and watch them make the diamonds at our leisure.”

“They don’t make them every day,” explained Renshaw.  “It seems they have to wait for certain occasions.  Mostly they make the diamonds when there’s a big storm.”