terrupted, this time in a more terrifying manner than before.

From the direction of the stream which they had left but a short time
previous, and undoubtedly from the boat itself, came the reports of
firearms. There were no shouts or outcries, but the firing was rapid
and apparently made by gun and pistol.

"They have been attacked!" exclaimed Mary; "we must go to their help!"

She impulsively started along the path, but her father seized her arm
and said sternly:

"Remain here! It is no place for you; Jack and I will do what we can."

Perhaps in the excitement of the moment the parent did not fully
comprehend the danger of leaving his daughter alone in the jungle, even
at so slight a distance and for so brief a time as he anticipated, with
nothing but a revolver as a means of defence; but he and Jack Everson
were eager to rush to the aid of their friends, and they hurried over
the trail without even looking back at her.

The young man was slightly behind his companion and both broke into a
loping trot. Each held his rifle in hand, on the alert to use it the
instant the opportunity presented itself.

It will be borne in mind that the distance from the slight natural
opening to the boat was short, and a few minutes sufficed for the two
men to cover it; but a strange thing happened. The reports of firearms
which had broken out with such suddenness ceased with the same
abruptness, and the silence because of the contrast was tenfold more
oppressive than before.

"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