"Paddle on, quick!" cried Ned in an agony of fear. "We may reach a break in the cliff."

Nugget, who was half a canoe's length in advance had sufficiently presence of mind to obey. He paddled off with desperate strokes, and Ned crowded him closely.

A few yards down stream the wall of rock jutted out slightly and then receded. As the canoes rounded this a great heaving wave—the vanguard of the flood—tossed them high on its crest and cast them, like a stone from a catapult, straight toward a black, semi-circular hole in the base of the cliff. A furious current swept in the same direction, and even had the boys realized the nature of this new peril they could have done nothing to help themselves.

Nugget dropped his paddle with a cry of terror and clutched the combing. The next instant he shot into the gaping hole, scraping his cap from his head by contact with the top, and disappeared from view.

Ned was dazed by what he had just witnessed, and his turn came before he realized it. He had hardly time to twist his paddle around longwise and duck his head when the current sucked him under the cliff. He heard a quick, grating noise, and then the dim gleam of light faded, leaving him in utter darkness.

The canoe pitched and tossed dizzily, and by the cold air that surged on his face, and the spray that spattered him, Ned knew that he was moving at rapid speed. Suddenly a cry rang in his ears with the sharpness of a pistol shot and reverberated through the cavern. An instant later he felt a violent concussion on the right, and reaching out his hand he touched the combing of Nugget's canoe.

He clung to it with all his might and managed to keep the two canoes side by side as the current whirled them on through the darkness.

Nugget was not aware of this at first, for he uttered another piercing cry for help. It was impossible to carry on any conversation owing to the confused booming noise made by the water, but Ned leaned to one side and shouted at the top of his voice: "Cheer up, Nugget. I'm here beside you. We'll find a way out of this."

Nugget must have heard and understood, for he was silent after that.

It was characteristic of Ned to cheer his companion. He was thoroughly unselfish, and was always more concerned about others than himself. In this case his consoling words meant nothing. He was still dazed by the overwhelming calamity that had befallen him, and had not begun to realize its extent.

He remembered the lantern that was in the forward hatch and the match safe in his pocket, but the former was out of reach and the latter was on his right side. He could not get it with his left hand, and he was afraid to trust the holding of the canoes to Nugget. So a light was out of the question at the present time.

The painful suspense of the next few minutes made them seem like hours. The canoes whirled on and on with a dizzy swaying motion, but not the faintest ray of light broke the intensity of the darkness.

Ned cautiously thrust his paddle out to the left, and it struck something hard with a ringing noise. He did not repeat the experiment for fear of upsetting.

All at once the roar of the water seemed to deepen, and the canoes settled into a swift, steady rush that made the air fairly sing about Ned's ears. What followed was never very clear to him afterward. He remembered a dash of icy spray in his face, and then a terrible collision that landed him somewhere on his hands and knees.

He was stunned and dizzy for a little while, and when finally he staggered to his feet his first thought was of Nugget. He called him by name, and a hollow groan was the only reply. Even that was better than silence, and with a trembling hand Ned drew out his match box and struck a light.

Both canoes lay upset at his feet, and between them was Nugget leaning on his elbows with a very dazed expression on his face.

Three more matches enabled Ned to right the Pioneer, procure his lantern, and light it. Then, seeing that Nugget was uninjured, he scrutinized his surroundings more closely.

He understood at once what had happened. The underground stream made a sharp curve at this point, and the force of the current had thrown the canoes far out on a sandy beach. From above, the yellow flood came roaring and tossing through a passage some twenty feet wide, and nearly the same in height. Below the angle it plunged on under the same conditions.

The beach was about ten yards long, and sloped back half that distance to a slimy wall of rock. On the opposite side of the stream the wall fell sheer into the water, and overhead was a jagged roof that glittered and sparkled in the rays of the lantern.

Ned formed his own conclusions as to the nature of the place, and they were not entirely unfavorable, for the speed and impetuosity of the muddy stream had given him a good deal to think about. He dismissed his reflections until a more favorable time, and placing the lantern on the sand turned to Nugget, who was in a pitiable state of fright.

"Are you hurt any, old fellow?" asked Ned, "or only a little stunned?"

"Oh, I don't know, I don't know," moaned Nugget. "What awful place are we in, Ned? It seems like a dream. I hardly remember what happened. And where are Clay and Randy?"

"I hope they are safe," replied Ned evasively. "In fact, I really think they are, Nugget. They landed some distance below us, and no doubt found a place to climb out before the flood caught them."

"And what happened to us, Ned? Didn't the current drag us into a hole in the cliff?"

"Yes," said Ned, "that's it exactly, and we are now in an underground cavern. Don't be alarmed," he added quickly, noting the sudden pallor on his companion's face, "our situation is not so terrible after all. Caverns of this sort are always found among limestone hills, and they usually have two outlets. This one is no exception to the rule, and I'll tell you why I think so. In the first place you must remember that the creek was nearly four feet high before that dam broke. The extra volume of water is what makes this terrific current through the cavern and the very fact that the water goes on through without damming up proves to me that it has an outlet.

"When the creek is at its normal level I don't believe any water flows into the cavern at all, and even with a four foot raise I don't think much goes through. It was the first rush of the flood that carried us into the hole. And now do you see what I am driving at? As soon as the back water from Honck's dam has spent itself—and it can't take very long—the stream in front of us will become shallow, and then all we need to do is to follow it down to the outlet. It probably cuts across some bend and re-enters the creek. And we have penetrated such a distance from the mouth that the outlet can't be far away. I can't swear to all this, Nugget, but I am pretty well convinced that I am right. A very short time will settle the question one way or another."

"I hope what you say will come true," replied Nugget dolefully. "This is a horrible place to be in. It gives me the shivers to think of it. But if all the water runs out, won't we have to leave our canoes behind?" he added quickly.

"We won't wait that long," said Ned. "Don't be downhearted. There is surely a way out of this cavern, and we'll find it. Our situation might be far worse than it is. We have matches and a lantern, and there are crackers in my canoe."

"Are there?" exclaimed Nugget eagerly. "I think I'll eat a few. You're an awfully good fellow, Ned. I don't feel half as bad now."

"It's a good sign to be hungry," replied Ned laughingly. He brought some of the crackers, and both ate them as they sat side by side on the sand.