It was not long after that that they heard the faint, warning noise that meant trouble ahead. A muffled roar came to their ears; it rose and fell in swells of sound like the vibrations of a bell. It was so far away, however, they could scarcely hear it. “You win, Miguel,” David said dejectedly. “It’s always that way,” Miguel replied. “I win when I want to lose and I lose when I want to win. Let’s make for the bank and stay close to it until we reach the rapids.” They dug the poles deep into the water and pushed with all their might. The raft responded gently to their efforts, but they knew it would drift downstream a great distance before reaching the bank. Before they had gone very far they realized that the rapids must be nearer than they had supposed for the roar was growing louder each minute and seemed to come out of the night no great distance ahead. Miguel was alarmed. “Faster,” he cried. “It’s just in front of us. We have to make the bank or we’re lost.” David shouted assent. He looked at the dark wall of trees still a good hundred yards off. Then he bent to his task with more force than before. In a few minutes it became obvious that their race was a doubtful one. The water surged and boiled as it rushed along at frightful speed and the raft began to lurch so that they could scarcely retain their footing, while the roar that now came to their ears was of thunderous volume. “We can’t make it,” David shouted finally. He had just estimated the span of angry water that still separated them from the land. “What will we do?” Miguel called in return. “It sounds too dangerous to attempt--at night. What do you say?” he added as David made no reply. “Wait!” David spoke quickly. “We can see a little way ahead and we can both swim.” Rocks of large size now loomed up in the riverbed. Around them the water raged and hissed in fretful torrents. But still the men kept their places, and inch by inch the raft drew toward the forested bank as it raced in the grip of the flood. David glanced up from time to time to appraise the water in front of them; its character would, of course, determine their course of action. “Quick,” he shouted suddenly, “that rock. Make for it for all you’re worth,” pointing to a black mass that rose out of the seething water in front of them, but ten yards to one side. Miguel did not know why his companion had come to the sudden conclusion that they should make for the rock; before, they had taken care to avoid obstructions of this kind. But there was no time to ask questions. He pulled with all the strength in his powerful frame in an effort to carry out the instructions that had been given him. The thing David had seen was a thin veil of mist rising into the moonlit sky. That one glimpse had been enough, for it meant that there was a waterfall below the haze. There was just time for the shout of warning to Miguel; their only hope lay in gaining the rock.