Suddenly in the midst of the crashing blows upon the door there was the report of a rifle. The Moors were adopting his own device of blowing in the lock. The door gave way, and by the flash of his torch, Tom saw a crowd of swarthy Riffians swarming through the opening. The door at the foot of the winding stair leading to the corridor was somewhat ruinous; it was apparently seldom used, the sheikh depending for his security upon the heavy trapdoor above. Tom, however, succeeded in pulling it to before the Moors were upon him, and shot the single crazy bolt that still held. Then he darted up the stairs after the rest. They were just lifting the envoy through the trap. Schwab was waiting his turn, and when he heard Tom rushing up, he sprang through the opening with extraordinary agility. The trapdoor was let down and bolted; they hastened up the stairway to the upper vestibule adjoining the guest-chamber, thence up to the sheikh’s quarters on the floor above, bolting every door behind them. Even through the thick walls of the kasbah they had heard sounds of great excitement in the town. Evidently the whole place was now alive. And there was danger to be anticipated within, for as they groped their way up the last flight of stairs leading to the roof, their steps momentarily guided by the flashes of Tom’s torches, the sounds of a tremendous battering near at hand struck upon their ears. Evidently the sheikh himself was now trying to make his way out. They hastened their steps as much as Sir Mark’s enfeebled state permitted; Tom indeed was in such desperate anxiety, for pursuit could not be long delayed, that he forced the pace in a way that drew a protest from the Englishman—even in this extremity a diplomatist. They came to the last flight of stairs leading to the roof. “Is that you, Dorrell?” came the voice of Oliphant from above. Nervously restless, first on account of Tom’s long absence, and then at the violent sounds within and without the building, he had left the airship and stationed himself with his revolver at the top of the staircase leading to the roof, to cover Tom’s retreat if he proved to be hard pressed. “All well!” shouted Tom in reply. In another minute all four emerged upon the roof, and Oliphant gave a whistle of amazement and consternation when he saw an unexpected addition to the party. “Two of them?” he ejaculated. “Yes; the sheikh had a German gentleman—” “Hildebrand Schwab, representative of ze excellent firma of Schlagintwert and——” “Hang it, we can’t stop for introductions now,” said Tom. “Abdul, run down to the door of the sheikh’s room and persuade him that he risks his life if he comes out. We shall want a minute or two to get ready.”