Geoff was not such a young soldier that he could not at once perceive the importance of the information just conveyed to him. With the knowledge he already had of Mesopotamia, he had been able to inform his friend on the Staff that, above the town of Basra, wide stretches of marsh would be discovered, which at certain seasons of the year were greatly extended by the heavy rains which fell in that part of the world. But if residence in Mesopotamia had given him some idea of the course of the rivers, of the towns and villages dotted here and there, and of the numerous peoples who inhabited that region, he could not, naturally enough, be expected to know where the Turks had disposed their forces on the outbreak of this gigantic war. Some had undoubtedly been posted towards the mouth of the Shatt-el-Arab, for had not the Indian horse already had a lively brush with them? But where were the others? Higher up the river, preparing their defences and waiting for the onward march of the British forces, or sneaking in those marshes to the west of them, which spread themselves along the broken and irregular course of the River Euphrates, from a point perhaps fifty miles away to the spot where the river joined with the main channel of the Tigris? And if they were there, hidden in the swamps, perhaps camping on some piece of ground elevated sufficiently to give them a dry footing, then indeed they would be a menace to the safety of the forces invading the country. They might march down along the edge of the swampy ground, or if provided with native boats, known as bellums, might steal over the shallow waters and cut off the retreat of Geoff and his comrades. "Chief," he said suddenly, "you know this marsh land, perhaps, and you would help us to discover these enemies?" "My master, an Arab is a man of the desert, a man who is happiest when far away in the open, or when mounted upon his horse, with leagues of sandy soil before him. We are not given to venturing upon the water, and thus it follows that I am ignorant of these marshes, and could be of little service. But listen, my master! There is one within this town of Basra who could assist you. A man known to me--a native of these parts, of uncertain nationality. He is but a poor fisherman; and if His Highness, whom I have met, cares to arrest him, he has then but to command and the man will carry out his bidding." "And suppose--for I must tell you, Chief, that we of Great Britain do not force our orders upon helpless and poor people--supposing a reward is offered to this man. What then?" asked Geoff.