“What can that mean?” asked Jack, as his companion slackened his pace.

“It means that they are through!” replied the doctor, whose face was of deathly paleness.  “My God! what have we escaped!”

“We shall soon know,” replied Jack, catching the awful significance of the words; and then he added to himself: 

“We may have escaped it, but for how long?”

A few rods further and they were at the side of the stream, and the boat loomed to view through the thick undergrowth and vegetation.

CHAPTER XV.

Gone!

Neither Jack Everson nor Dr. Marlowe forgot his own personal danger in hurrying to the help of their imperilled friends.  If the two were too late to be of any assistance they were imminently likely to precipitate themselves into the same whirlpool of woe and death.  They had slowed their gait to a walk as they neared the spot, and when they caught the dim outlines of the boat the two stood still.

So far as they could see there was no change in its surroundings.  It was still moored against the bank, so close that any one could step aboard, but no sign of living person was visible on or about it.  There was something so uncanny in it all that but for their mutual knowledge they would have doubted the evidence of their senses.

“I don’t understand it,” whispered Jack.  “Suppose you stay here while I steal nigh enough to learn something that will help clear up the horrible mystery.”

“You are running frightful risk,” said the doctor; “I cannot advise you to try it.”

“All the same, I shall do it.”

Thus, it will be observed that the three persons composing the little party became separated from one another for greater or less distances.  The daughter was waiting, two or three hundred yards away, for the return of her father and lover, while they had just parted company, though they expected to remain in sight of each other.

Dr. Marlowe stood in the path, partly sheltering himself behind a couple of tree trunks, but with his eyes fixed upon his young friend, who walked cautiously but unhesitatingly forward.  Jack held his rifle in a trailing position at his side, his shoulders bent slightly forward, while he stepped lightly, his senses alert, like those of a scout entering the camp of an enemy.  That he was running into great danger was self-evident, but he was determined not to turn back until he learned something of the strange occurrences.

Watching his young friend, the doctor saw him stop when at the side of the motionless boat.  His profile showed first on one side and then, on the other, while he listened for the slightest sound that could give an atom of knowledge.  Apparently the effort was useless, for the next moment he placed his left hand on the gunwale and vaulted lightly upon deck.  He stood a few moments as if transfixed, then turning abruptly about leaped to the ground, and, breaking into a run, hurried back to his friend, who noticed that his face was more ghastly than before, while his eyes stared as if they still looked upon unutterable things.