CHAPTER XVI.

BURIED IN AN UNDERGROUND RIVER.

When Mark felt himself flying from his horse's back through the air, he of course expected to strike heavily on the ground, and nerved himself for the shock. To his amazement, instead of striking on solid earth he fell into a mass of shrubbery that supported him for a moment, and then gave way. He grasped wildly at the bushes; but they were torn from his hands, and he felt himself going down, down, down, and in another instant was plunged deep into water that closed over his head. He came to the surface, stunned and gasping, only to find himself borne rapidly along by a swift current. He did not for a moment realize the full horror of his situation, and with the natural instinct of a swimmer struck out vigorously.

He had taken but a few strokes when his hand hit a projecting rock, to which he instinctively clung, arresting his further progress. To his surprise, on letting his body sink, his feet touched bottom, and he stood in water not much more than waist deep, but which swept against him with almost irresistible force.

His first impulse was to scream, "Frank! oh, Frank!" but only a dull echo mocked him, and he received no reply but the rush and gurgle of the water as it hurried past.

Then in an instant he comprehended what had happened. He had been flung into a "sink hole," and was now buried in the channel of one of those mysterious underground rivers of which Mr. March had told them a few nights before. That was at home, where he was surrounded by his own loving parents and friends. Should he ever see them again? No; he was buried alive.

Buried alive! he, Mark Elmer? No—it couldn't be. It must be a dreadful dream, a nightmare; and he laughed hysterically to think how improbable it would all seem when he awoke.

But he felt the cold water sweeping by him and knew it was no dream. The reality stunned him, and he became incapable of thinking; he only moaned and called out, incoherently, "Mother! father! Ruth!"

After a while he began to think again. He had got to die. Yes, there was no escape for him. Here he must die a miserable death, and his body would be swept on and on until it reached the Gulf and drifted out to sea; for this running water must find its way to the sea somehow.

If he could only reach that sea alive! but of course that was impossible. Was it? How far is the Gulf? And the poor boy tried to collect his thoughts.