Presently his hand came in contact with the trunk of a tree, that had fallen and had been partly embedded in the mud. It afforded a precarious foothold, but proceeding carefully, Denbigh found that the farther end rested in comparatively firm soil. Planting his feet against the trunk, the sub hauled at the lead-line with all his might. The flat-bottomed punt glided easily over the slime until its bows were within a yard of the fallen tree. Then, unexpectedly, the rope that had rendered such good service parted like pack-thread. Denbigh, losing his balance, fell prostrate on the ground, which was here soft enough to break his fall but sufficiently stiff to prevent him from being swallowed up in the mud. Quickly O'Hara and Armstrong jumped, and grasping their fallen comrade hauled him to his feet. They had barely time to gain the firm bank when the bore thundered past, sweeping the punt away like a straw. They had a momentary glimpse of its bows rearing high in the air on the crest of the foaming, breaking wall of water, then it vanished out of sight. "Phew!" exclaimed Armstrong. "That was a narrow squeak." "I'm in a horrible mess," announced Denbigh. "The mud of Portsmouth Harbour is eau de Cologne compared with this filthy slime." "Good heavens, man! you're shivering," declared O'Hara. "That won't do. Here, take my coat. I don't want it. I insist." Waving aside Denbigh's objections the Irishman made him take off his saturated garments, while the rest of the deficiency of the sub's wardrobe was temporarily made good by making use of Armstrong's silk scarf as a loin-cloth. The men realized that in the deadly African climate dry clothing was of utmost importance. The sub's saturated and mud-encaked garments were made up into a bundle to be washed and dried at the first opportunity. "Now," said Denbigh, "I feel like a giant refreshed. We've plenty of time, for it's no use getting to the coast before sunrise. If you fellows like to wait here I'll go up along the banks and see what is at the shore end of that chain." "It isn't going to be a one-man show," objected O'Hara. "We'll all have a chip in. You lead, if you will, old man. I'll follow just far enough behind to keep you in view. Armstrong, will you bring up the rear?" In single file and extended order the three officers made their way towards their objective. Keeping just below high-water mark they found the ground easy to walk upon, and, with one exception, free from the presence of crocodiles. One huge brute barred their path, but on Denbigh hurling a heavy stick in its direction, the saurian turned and waddled towards the water. Noiselessly, for the soft ground effectually deadened the sound of their footsteps, the daring explorers advanced. Suddenly a hoarse voice broke the silence with a guttural "Wer da?"