Its two occupants were Lieut. José Sancho and Lieut. Manuel Diaz of the Mexican army. They had been flying since daybreak, scouting the country thoroughly in search of information of the rebels’ whereabouts. The great flock of buzzards had attracted their attention, and Lieut. Sancho, who was at the wheel, while his comrade scanned the country through field glasses, had steered the airship in the direction of the great birds. “Can you see anything?” he asked Lieut. Diaz as the airship drove in among the birds, scaring them off with hoarse cries. “Yes. There is something on the ground.” “It must be some dead animal. No human being could have found his way into this miserable desert.” Lieut. Sancho was about to put the airship on its course once more when his brother officer gave a startled exclamation. “By the saints!” he exclaimed, “this is strange.” “What do you mean?” “Why, what attracted those buzzards was no dead steer or horse.” “What then was it?” “The figure of a boy or a man lying face downward.” “Is he dead, do you think?” “It is impossible to tell.” “Shall we descend and see?” “We might as well, although, to speak the truth, I can’t conceive that anyone could have wandered into this desert and lived.” “Nor I. Still it is our duty to find out.” “Undoubtedly. Let us land on that little hillock yonder and then we can make an examination.” Down swooped the great airship, landing without a jar on the bare little hill Lieut. Diaz had mentioned. As soon as the craft touched the ground the two Mexican officers were out of it, and, after attending to the motor, hastened over the sandy soil to Jack’s side. “_Santa Maria!_ It is but a boy,” exclaimed Lieut. Sancho as he turned the inanimate form over. “_Todos los Santos_, so it is. A fine–looking fellow, too. But is there any trace of life in him?” For answer Lieut. Sancho shook his head mournfully. “I fear we have come too late,” he said, bending over Jack to try to catch the least flicker of life. CHAPTER XVIII. THE SANDSTORM. His companion produced a tiny mirror, part of a pocket toilet set he carried. Lieut. Sancho took it and held it over Jack’s lips. “Praise the saints, there is still life in him. See!” He held up the mirror for his companion’s inspection. It was blurred faintly, showing that the boy was still breathing. “Get the emergency outfit,” was the next order of the young Mexican officer, and his companion soon produced the required kit from a box under the seat of the military biplane. The kit was the same as used by the armies of most civilized nations. It contained, besides bandages and antiseptics for wounds, stimulants and other drugs. Forcing Jack’s lips open, the lieutenant gave him some stimulant, and was rewarded before long by a faint stirring on the part of the boy.