Tisco held out a fine linen handkerchief, with an embroidered initial “H” in one corner.  Harry was fond of fine linen, and effected these handkerchiefs.

“Yes; it’s mine, thank you,” nodded Harry, accepting the proffered bit of linen and pocketing it.

“I found it in a field, just this side of El Sombrero,” remarked Tisco, artlessly, turning away.

Though the secretary did not watch Hazelton’s face, Don Luis did, and saw the slight start of surprise and the flush that came to the young engineer’s face.

“You, too, have been walking then, Senor Hazelton?” inquired Don Luis, pleasantly, though with an insistence that was not to be denied.

Harry didn’t know how to lie.  He might have dodged the question, but he was quick enough to see that evasion would make the matter worse.

“Tom and I took a stroll last night,” he admitted, indifferently.  “How far did we go, Tom?”

“Who can say?” replied Reade, lightly.  “It was so dark, and the way so unfamiliar that we were glad when we got home, I know.”

“They have been prowling,” muttered Don Luis, sharply, under his breath.  “I must have them watched.”

“Are we going to the mine this morning, Don Luis?” Tom asked, carelessly.

“Do you care to go, Senor Tomaso?”

“Why, that’s just as you say, sir,” Reade rejoined.  “Of course, we would like to get actively engaged at our work.  In fact, it seems to me that Harry and I should rise earlier and be at the mine at least from eight in the morning until six at night.”

“You would soon tire yourselves out.  The mine is a dirty hole.”

“By the way, sir,” Reade went on, carelessly, “how far do you have to send ore to have it smelted.”

“About sixty miles.”

“By mule-train, I suppose.”

“Yes, Senor Tomaso.”

“It must be costly shipping.”

“So it is,” sighed Don Luis, “and yet the ore is rich enough to bear easily the cost of shipping.”

“In what direction is the smelter?”

Don Luis pointed.

“Straight ahead, as I am showing you,” he added.

“We saw the lights of a train last night,” Tom went on.  “I judged that the mule-train came from the mines above.  Yet the mule-train did not follow the direction that you have just shown me.  The road runs crooked, I take it.”

“Oh, yes,” nodded their host, as carelessly as Tom had spoken.

“Do the other mines pay as well as El Sombrero?”

“Oh, no, Senor Tomaso,” Montez replied quickly.  “The other mines yield not anywhere near as rich ore as comes from El Sombrero.”

“Are you going to take us to see the other mines?” Tom hinted.

“Gladly would I do so, Senor Tomaso, only I am not on good terms with the owners.”

“I’m sorry,” Tom sighed.  “While we are here I wish that we could see much of Mexican mines.  Nevertheless, when we are through here I have no doubt that you can give us letters to other mine owners.”