They went steadily down the river, the men keeping pace with them as closely as possible, though the nature of the ground caused them sometimes to leave the bank and march at a considerable distance from it. For nearly two hours, as they guessed, they did not catch a single glimpse of the enemy, and hoped that they had tired of the pursuit. But presently they had reason to suspect that they were not to be allowed to escape so easily. The river spread out into a kind of swamp, apparently almost half-a-mile in breadth. About half that distance ahead it was studded with small wooded islands, and Ferrier, who was still leading, was puzzled as to which of the channels into which the stream was divided was the safest to attempt. The enemy were not in sight, but from somewhere ahead came the sound of chopping wood. "What are they up to?" said John. "Can’t tell. Making a boma perhaps. Don’t you think we had better take the men on board before we get fairly into the swamp? If the enemy are hidden on those islands we had better have them with us." John hailed the marching men, who came at his call and were soon ensconced on the rafts again. They punted along, looking ahead warily for signs of the enemy. The current became more and more sluggish, and there was at times scarcely enough water to float the rafts, now again weighted by their passengers. Ferrier scanned the river in search of a practicable channel. In the channels on the left he saw mud-banks rising just above the surface. A wider channel to the right, about twenty yards broad, gave the best promise of a safe passage, and towards this he steered. While still some distance from it, however, he saw some figures emerge from the wooded island on the left, wade hurriedly across, and enter a similar wood on the right bank of the river, both the island and the bank being here slightly above the level of the water. The greater number of the waders were negroes, but among them were the white-clad forms of Swahilis. "This is nasty," said John. "We can’t go back." "Nor forward either, except at a snail’s pace," said Ferrier. "Confound it! We’re stuck again. Look out, John: I’m on a mud-bank. Pull up till I’m free." By dint of energetic poling he managed to get his raft clear. John avoided the obstacle by slightly changing his course. "All we can do," he said, "is to push on as fast as we can and trust to the breastwork. The worst of it is, the men can’t defend themselves without exposing their heads to the enemy’s fire." "Yes they can, if they make loopholes," replied Ferrier. "Set ’em to cut some; we were idiots not to do it before."