He got to his feet slowly and walked up and down the room for a moment, glancing out occasionally towards the clump of palms which marked the disappearance of the Nile into the desert beyond his vision. At intervals a cannon-shot crashed upon the rarefied air, as scores of thousands had done for months past, torturing to ear and sense and nerve. The confused and dulled roar of voices came from the distance also; and, looking out to the landward side, David saw a series of movements of the besieging forces, under the Arab leader, Ali Wad Hei. Here a loosely formed body of lancers and light cavalry cantered away towards the south, converging upon the Nile; there a troop of heavy cavalry in glistening mail moved nearer to the northern defences; and between, battalions of infantry took up new positions, while batteries of guns moved nearer to the river, curving upon the palace north and south. Suddenly David's eyes flashed fire. He turned to Lacey eagerly. Lacey was watching with eyes screwed up shrewdly, his forehead shining with sweat. "Saadat," he said suddenly, "this isn't the usual set of quadrilles. It's the real thing. They're watching the river--waiting." "But south!" was David's laconic response. At the same moment he struck a gong. An orderly entered. Giving swift instructions, he turned to Lacey again. "Not Cairo--Darfur," he added. "Ebn Ezra Bey coming! Ali Wad Hei's got word from up the Nile, I guess." David nodded, and his face clouded. "We should have had word also," he said sharply. There was a knock at the door, and Mahommed Hassan entered, supporting an Arab, down whose haggard face blood trickled from a wound in the head, while an arm hung limp at his side. "Behold, Saadat--from Ebn Ezra Bey," Mahommed said. The man drooped beside him. David caught a tin cup from a shelf, poured some liquor into it, and held it to the lips of the fainting man. "Drink," he said. The Arab drank greedily, and, when he had finished, gave a long sigh of satisfaction. "Let him sit," David added. When the man was seated on a sheepskin, the huge Mahommed squatting behind like a sentinel, David questioned him. "What is thy name--thy news?" he asked in Arabic. "I am called Feroog. I come from Ebn Ezra Bey, to whom be peace!" he answered. "Thy messenger, Saadat, behold he died of hunger and thirst, and his work became mine. Ebn Ezra Bey came by the river. . . ." "He is near?" asked David impatiently. "He is twenty miles away." "Thou camest by the desert?" "By the desert, Saadat, as Ebn Ezra effendi comes." "By the desert! But thou saidst he came by the river." "Saadat, yonder, forty miles from where we are, the river makes a great curve. There the effendi landed in the night with four hundred men to march hither. But he commanded that the boats should come on slowly and receive the attack in the river, while he came in from the desert."