“No,” said the mine owner.  “And, on my part, I promise you that, if I sell the mine, as I now surely shall do, you shall have twenty thousand dollars, gold, apiece, and your lives also.  Here is my hand on the pledge of an hidalgo.”

Don Luis shook hands with both American engineers.  Even as he did so a wolfish gleam crept into his eyes.  Montez, in his mind’s eye, already saw the two Gringos stretched on the ground in death in a remoter part of the mountains.  That was to be his real reward to the young dupes of his villainy.

“When do you expect your purchasers?” Tom Reade inquired.

“Two days after to-morrow, Senor Reade.  But, in the meantime, now that we are friends and really partners—­will you not come over and share the comforts of my poor home while we wait?”

“You will pardon us for not accepting, Don Lids,” Tom urged.  “We have met your wishes, and shall continue to meet them, but we feel that we would rather remain where we are—­at least, until your visitors arrive.”

“So be it, then,” muttered Don Luis.  Yet he appeared slightly offended by their decision.  Since the young engineers had now proved themselves to be as great rascals as he himself, Don Luis Montez could not understand why they should refuse to associate with him.

“You wish me to leave you alone, now?” asked the mine owner, smiling rather coldly.

“Only when you wish to leave us, Don Luis,” Tom protested, so artlessly that the Mexican felt less offended.

“Sit down and chat with us until you tire of our company,” urged Harry Hazelton.

So Montez and Tisco dropped into the campstools again.  They tried to chat on various topics, but conversation proved a failure.

“We will go, now,” said Don Luis, rising twenty minutes later.  “But, senores, we shall hope to see you daily until our investors arrive and then all the time.”

“You will find us always at your command, Don Luis,” Tom remarked, cordially.

“Ah, my good Carlos,” murmured Don Luis, as the Mexican pair sped homeward in the car, “for once you made a bad guess.  You insisted that the Gringos would hold out and would not serve me.  You have seen my patience and my firmness win over their foolish, stubborn objections.”

“But they still hope to trick you, my patron,” suggested Dr. Tisco.  “Doubtless, now, their intention is to serve you until they can escape; then they plan to get back to the United States and furnish the testimony on which the American investors can sue you in the courts for the return of the purchase money on a charge of fraud.”

“There, again, the Gringos can meet only defeat,” chuckled Don Luis, his lips to his secretary’s ears.  “As soon as the sale is made I shall see to it that our pair of young American engineers are promptly done to death!”

CHAPTER XXI

THE FINAL TOUCH OF TRAGEDY