To begin with, he had lost a whole day. With the utmost expedition, and no accidents, he could hardly reach the _tell_ at the time appointed with Captain Ellingford. Moreover, the horse, to which he owed his escape, was now an encumbrance and an embarrassment. The remainder of his journey lay over a parched and barren plain, that provided sustenance for neither man nor beast. The small stock of dates which he had purchased in Meshed Ali would suffice for himself, but not for the horse as well. True, the Arab horse was accustomed to go long distances with little or no food, but it would be two days at the best before he reached the _tell_, and two days' fast was beyond even the Arab's endurance. Further if by good luck he should meet Captain Ellingford--and that was now doubtful--what could he do with the horse then? He could not return to the British lines except by aeroplane: yet it went much against the grain to abandon the noble animal that had served him so well. If turned adrift and left to forage for himself, the horse would probably pick up a subsistence until he found a new master. A new master! In these regions that could hardly be any one than an enemy. Turkish troops were constantly on the move in the plains between the Euphrates and the Tigris. Burnet was loth to let his prize fall again into Turkish hands. The problem how to save the horse and yet not fail in his appointment with Captain Ellingford was a very hard nut to crack. When Burnet had pondered the question for some time, a light suddenly dawned upon him. The stronghold of the young chief Rejeb, which he had heard described in the course of the interview between General Eisenstein and Major Burckhardt, was about one march distant from the _tell_, in a south-easterly direction. As nearly as he could judge, the spot where he had crossed the river was almost due south of the _tell_. In all probability, then, the stronghold was not less than fifteen nor more than twenty-five miles to the east. Could he discover the stronghold, leave the horse in Rejeb's care, and yet keep his appointment with Captain Ellingford? There were several circumstances to take into consideration. In the first place, it was clear from what the Germans had said that the stronghold was not easy to discover. Its locality was not well known to the authorities in Bagdad; they had had recourse to Major Burckhardt; it was certain that Rejeb had chosen a place far from the tracks of the desert travellers, and by its very nature hard of access. Then, too, the expedition organised against it might already be on foot; the stronghold might, indeed, have already fallen. To approach it might be to jump into the lion's jaws. On the other hand, General Eisenstein had anticipated delay. The month he had allowed for the organisation of the expedition was barely up, and there might be time to gain the stronghold before operations began, and, indeed, to give Rejeb warning of what was to come.