We had just discussed the matter, and had determined to encourage the same fond relationship with our prospective mounts, when MacFarlane rode up to the hotel with the five most woebegone-looking specimens of quadrupeds that we had ever seen.

“Cut a good big stick,” he advised.

Two minutes after mounting, I welcomed the suggestion. It seemed inhuman to beat anything so small as that mule, but the animal appeared not to mind it in the least. The moment I ceased whaling him, he assumed that this was where I wished to stop. His one virtue was that no matter how often he stumbled on the edge of a precipice, he never fell over.

“When you come to a tight place,” warned MacFarlane, “let the mule use his own judgment.”

And there were plenty of tight places. Hour after hour the path twisted through narrow ravines, along deep water-courses strewn with bowlders, down sandy embankments where the animals slid like toboggans, around narrow cliffs, and up sharp inclines where they fairly leaped from rock to rock. It was a gloriously desolate country, hideous perhaps, yet awesome in its ugly grandeur. Mountains reared themselves above the trail, covered sometimes with huge candelabra cactus, but usually bare and towering skyward like the battlements of a gigantic fortress. So fascinating was the whole panorama that four of us rode across a valley a full mile in length before we discovered that Eustace had disappeared.

MacFarlane stopped abruptly.

“Good Lord! I told him to keep close to us! Four months ago one of my men dropped behind, and they nabbed him so quietly we never heard a sound!”

He was off his mule in an instant, and leading the way on foot, revolver in hand, while I followed at his heels, both of us crouching behind bowlders as we hurried back along the path we had traversed. Turning a bend, we found Eustace sitting on his mule at the top of a sandy decline, complacently smoking a cigar.

“What the devil are you doing?” snapped MacFarlane.

“Tight place,” said Eustace. “I’m letting the mule use his own judgment.”