"What are they?" she called out to Mustafa Ali, who had dropped some way behind her. But he, too, was looking back at the horsemen, and did not seem to hear her question. Her escort had lagged still further behind her guide and were some distance away. Diana watched the rapidly moving, compact square eagerly with appreciatory eyes--it was a beautiful sight. Then she gave a little gasp. The galloping horses had drawn level with the last stragglers of her own party, and just beyond they stopped suddenly. Diana would not have believed it possible that they could have stopped so suddenly and in such close formation while travelling at such a pace. The tremendous strain on the bridles flung the horses far back on their haunches. But there was no time to dwell on the wonderful horsemanship or training of the men. Events moved too rapidly. The solid square split up and lengthened out into a long line of two men riding abreast. Wheeling behind the last of Mustafa's men they came back even faster than they had passed, and circled widely round Diana and her attendants. Bewildered by this manoeuvre she watched them with a puzzled frown, striving to soothe her horse, who was nearly frantic with excitement. Twice they galloped round her little band, their long cloaks fluttering, their rifles tossing in their hands. Diana was growing impatient. It was very fine to watch, but time and the light were both going. She would have been glad if the demonstration had occurred earlier in the day, when there would have been more time to enjoy it. She turned again to Mustafa Ali to suggest that they had better try to move on, but he had gone further from her, back towards his own. She wrestled with her nervous mount, trying to turn him to join her guide, when a sudden burst of rifle shots made her start and her horse bound violently. Then she laughed. That would be the end of the demonstration, a parting salute, the _decharge de mousqueterie_ beloved of the Arab. She turned her head from her refractory horse to look at them ride off, and the laugh died away on her lips. It was not a farewell salute. The rifles that the Arabs were firing were not pointing up into the heavens, but aiming straight at her and her escort. And as she stared with suddenly startled eyes, unable to do anything with her plunging horse, Mustafa Ali's men were blotted out from her sight, cut off by a band of Arabs who rode between her and them. Mustafa Ali himself was lying forward on the neck of his horse, who was standing quiet amidst the general confusion. Then there came another volley, and the guide slid slowly out of his saddle on to the ground, and at the same time Diana's horse went off with a wild leap that nearly unseated her.