Tom did not follow the advice to flatten himself on the ground.  Instead, he stood straighter—­even rose on his toes and stared in the direction whence he judged the shot to have come.

“Gato, you treacherous scoundrel!” Read roared, in Spanish.  “Do you call yourself a brave man, to fight an unarmed foe like this?”

All was silent amid the rocks in the distance.

“Have you too little courage to answer me?” Tom again essayed.  “Or are you man enough to show yourself—­to come forward and listen to me.  Don’t be afraid.  I can’t hurt you.  I have no weapon worse than my fists.”

As the young chief engineer spoke in Spanish, Nicolas understood.

“Don’t!  Don’t, mi caballero,” implored the Mexican servant “Don’t let him know that you are unarmed.  Make a move as though to draw a pistol, and Gato may run away instead of sighting his rifle once more at you.”

“Now I know you, Gato, for the wolfish coward that you are,” Tom Reade shouted mockingly.  “You are desperately afraid when you won’t meet me, unarmed as I am.”

“If Senor Reade is so utterly brave when he has no weapons,” thought the barefooted servant, “then if he had a gun in his hand he would be the bravest man in all the world!”

“I guess that yellow dog isn’t going to bark at us again, just now,” laughed Tom, carelessly, when some moments had passed without another shot.  “Doubtless, the fellow was frightened away by the sound of his own rifle.”

“That shot was a warning,” chattered Nicolas.  “It is his way of sending you his defiance.  When Gato fires again he will try in earnest to kill you, and he will keep on firing until he succeeds.  Oh, mi caballero, if you will give me some more of your Americano money, I will hasten about until I find some one who will sell me a gun for you.  You must have one in your hands all the time.”

“Not for mine,” smiled Reade.  “To tell you the truth, Nicolas, guns sometimes make me nervous.  If I had one I might be clumsy enough to shoot myself with it.”

“Nicolas is talking sense,” interrupted Hazelton, speaking in English.  “Both you and I should be armed.”

“By all means have Nicolas get a gun for you, Harry, if you will,” Reade answered, coolly.  “But none for me.”

“I’d like to meet Gato face to face and on equal terms,” Harry went on, dropping back into the Spanish tongue.

“So would I,” agreed his chum.  “I have much to say to Gato.  If there were mail boxes in this wild country I’d drop him a letter.”

“Do you really wish to send Gato a letter?” asked Nicolas, eagerly.

“Why, I’d send him one if I could,” nodded Tom.

“Have you writing materials?” pressed the servant.

“Yes—­but what’s the use?”

“Write your letter, mi caballero, and I will hand it to Gato,” urged the Mexican.

“You?” gasped Tom.