Mr. Hampton slid into position beside them. His approach had been soundless. He appeared worried, and laid a finger on his lips to enjoin silence and, as Jack half rose, pulled him down beside him. Then motioning Frank to draw near, he whispered the startling information that a troop of horsemen was approaching along the Great Road from the direction of Korakum.

“The scout sent up the Great Road brought back the information several minutes ago,” he whispered, “and as he said the horsemen still were some distance off, I sent him down the pass to bring in the man stationed there, who, otherwise, would have been cut off. Both have just returned. I suppose you fellows were too busy to notice what was going on. Get your rifles and come along.”

Without further words, he turned and walking bent over made his way back toward the front of the plateau where Ali and his Arabs awaited. The boys, with beating hearts, seized their rifles and followed.

What did this portend? Was the band of horsemen coming to attack them? Had they been discovered? Or were the Athensians riding out to meet and escort back the raiders? Either contingency spelled disaster to their project for Bob’s rescue. Frank and Jack felt their hearts sink.

The front of the plateau, at the edge of a terrace sloping ten feet down to the road, was narrow. Their force of ten was sufficient to defend it, as Mr. Hampton had said, against an army. Lying down, a yard or two apart, they were able to cover it completely. Moreover, the thick underbrush afforded an effective screen against detection. Unless it were known they were there, or unless their presence was betrayed by some noise made by the camels, they could lie securely hidden.

Little time for speculation was afforded. Barely had the boys crept into the holes left for them in the center of the line, between Mr. Hampton and Ali, when the ringing sound of horses’ hoofs, echoing between high walls, announced the near approach of a considerable body of horsemen.

Then around the next bend above them came the leaders of the troop, riding four abreast, with loose rein, and followed by rank on rank, until a full hundred men appeared. In the lead rode the captain on a splendid black horse, not large, but beautifully built, a perfect thoroughbred. This captain was a young man, still in his thirties, beardless, bronzed, with the same hawklike nose of Amrath. The men in rank were some young, some middle-aged, and their appearance was startling. No two were dressed alike, although some form of the knee-length toga was worn by all. Some wore leggings, others rode bare-legged. Some wore remarkable helmets, not on their heads, but dangling at saddle bow, helmets of curious and exquisite workmanship. Some wore shirts of mail, of very fine links. One or two wore steel corslets. For arms, all carried long bows, quivers of arrows slung across their backs, short heavy swords by their sides like those carried by the ancient Roman centurions, and heavy spears. Perhaps a third also carried rifles.

Rank on rank this troop rode past the plateau without conversation in the ranks, each man sitting easily in the saddle, grim faced or thoughtful. On every face was a look of fine intelligence, and quite evidently the force was composed of superior men.

Jack and Frank were in a daze, lying with eyes glued to the strange sight, unable to puzzle out the meaning. Was this a troop of Athensian cavalry? Then why the ragged dress of the riders? As for Mr. Hampton, he, too, wondered, recalling that Amrath had said the common people of Athensi were steeped in ignorance. So, too, would be the Janissaries of the priest clan. Yet these men, stern and grim-faced all, looking like fighters, yet also had an appearance of great intelligence which he could not reconcile with his preconceived opinion of what the soldiers would be like.

Bathed in the sunlight which fell into the canyon from almost directly overhead, so that the windless air was close and languid, the troop passed quickly, and the last rank came in sight. Only three men rode in it, and as they came abreast of Mr. Hampton one of this number, a fine looking young fellow of medium height, with crisp curling hair lying damp on his bared forehead, turned in the saddle and called to the fourth man some distance in the rear: