A retort trembled on Diana's lips, but her attention was distracted from her annoying guide to a collection of black specks far off across the desert. They were too far away for her to see clearly, but she pointed to them, peering at them intently. "See!" she cried. "Is that the caravan?" "As Allah wills!" he replied more piously than before, and Diana wished, with a sudden feeling of irritation, that he would stop relegating his responsibilities to the Deity and take a little more active personal interest in his missing camel train. The black specks were moving fast across the level plain. Very soon Diana saw that it was not the slow, leisurely camels that they were overtaking, but a band of mounted men who were moving swiftly towards them. They had seen nobody since the traders' caravan had passed them in the morning. For Diana the Arabs that were approaching were even more interesting than the caravan had been. She had seen plenty of caravans arriving and departing from Biskra, but, though she had seen small parties of tribesmen constantly in the vicinity of the town, she had never seen so large a body of mounted men before, nor had she seen them as they were here, one with the wild picturesqueness of their surroundings. It was impossible to count how many there were, for they were riding in close formation, the wind filling their great white cloaks, making each man look gigantic. Diana's interest flamed up excitedly. It was like passing another ship upon a hitherto empty sea. They seemed to add a desired touch to the grim loneliness of the scene that had begun to be a little awe-inspiring. Perhaps she was hungry, perhaps she was tired, or perhaps she was only annoyed by the bad arrangements of her guide, but before the advent of the mounted Arabs Diana had been conscious of a feeling of oppression, as if the silent desolation of the desert was weighing heavily upon her, but the body of swiftly moving men and horses had changed the aspect utterly. An atmosphere of life and purpose seemed to have taken the place of the quiet stagnation that had been before their coming. The distance between the two parties decreased rapidly. Diana, intent on the quickly advancing horsemen, spurred ahead of her guide with sparkling eyes. They were near enough now to see that the horses were beautiful creatures and that each man rode magnificently. They were armed too, their rifles being held in front of them, not slung on their backs as she had seen in Biskra. They passed quite close to her, only a few yards away--a solid square, the orderly ranks suggesting training and discipline that she had not looked for. Not a head turned in her direction as they went by and the pace was not slackened. Fretted by the proximity of the galloping horses, her own horse reared impatiently, but Diana pulled him in, turning in her saddle to watch the Arabs pass, her breath coming quick with excitement.