at there were shipwrecked people in these caves.
How could they help knowing it, if they had killed Davis and the others?
But, cowardly hounds as they were, they had been afraid to attack the
place until they knew how many people were in it, what arms they had, and
in what way the place could best be assailed. This Mok had found out
everything. If the boy could swim across the lake, that black man could
do it, and he had gone out through the cleft, and was probably now making
his report to the gang.

All this flashed through the captain's brain in a few seconds. He set his
teeth together. He was ashamed that he had allowed himself to be so
tricked. That African, probably one of the gang, and able to speak
English, should have been kept a prisoner. What a fool he had been to
treat the black-hearted and black-bodied wretch as one of themselves, and
actually to put him on guard!

Of course, it was of no use to go to look for him, and the captain had
put down his gun, and was just about to turn to speak to the others, when
Maka seized him by the coat. The negro seemed wildly excited and still
unable to speak. But it was plain that he wanted the captain to follow
him along the passage. There was no use in asking questions, and the
captain followed, and behind him came Ralph, Edna, and Mrs. Cliff.

Maka was about to climb over the rocky partition which divided the
passage, but the captain stopped him. "Stay here," said he, "and watch
the passage. I will see what is the matter over there." And then he and
Ralph jumped over and hurried to the lake. As they came out on the little
platform of rock, on which the evening light, coming through the great;
cleft, still rendered objects visible, they saw Mok crouching on his
heels, his eyes wide open as usual.

The captain was stupefied. That African not gone! If it were not he,
who had gone?

Then the captain felt a tight clutch upon his arm, and Ralph pulled
him around. Casting eyes outward, the captain saw that it was the lake
that had gone!

As he and Ralph stood there, stupefied and staring, they saw, by the dim
light which came through the opening on the other side of the cavern, a
great empty rocky basin. The bottom of this, some fifteen or twenty feet
below them, wet and shining, with pools of water here and there, was
plainly visible in the space between them and the open cleft, but farther
on all was dark. There was every reason to suppose, however, that all the
water