rother to take a position on the narrow ledge. It
was barely wide enough for two, but, somehow, they managed to cling to
it. The surface was wet, and there were little puddles of water here
and there. Seeing them in the gleam of his light, Frank could not
repress a shudder.

"The tide must come up even to here," he thought. "If it comes up to
the roof--well, that's the end of us." But he said nothing to Andy.

Slowly the water rose. They boys watched it, sitting on the narrow
ledge with their feet and legs dangling off. From time to time Frank
would flash his light on the little lapping waves.

"It will soon stop," he said, as cheerfully as he could. But he did
not believe himself. He held Andy's hand in a firm grip.

Higher and higher rose the tide. It was at the knees of the boys now,
and still mounting.

"Let's stand up," proposed Frank at length. "I'm tired of sitting."

They took an upright position on the ledge of rock. Their heads just
touched the rocky roof of the cave. In fact Frank, who was a trifle
taller than his brother, had to stoop.

"Now we'll be all right, Andy," he said. "We can stand here until the
water goes down."

"If--if it doesn't touch the roof," was the solemn answer.

Frank said nothing.

Standing on the ledge, high above the floor the cave, the water now
lapped their ankles once more. Frank could feel it creeping
higher--ever higher. In spite of himself, a horrible fear took
possession of him. Death was very near, he thought--a terrible death
by drowning in the cave where they were caged like rats in a trap.

CHAPTER XXII

THE STORM

"Do you know how high the tide rises on this island?" asked Andy after
a pause. His voice sounded strange in that hollow, dark place, amid
the ceaseless lapping of the water on the rocks.

"How high? No, but it can't get much higher," answered Frank as
cheerfully as he could. "It's been rising some time now, and it must
stop soon."

"It seems a long time, but it isn't," went on Andy in that quiet voice.
"Look, it's seven o'clock," and he held out his watch, illuminating it
with the flashing electric light.

"Seven in the evening," murmured Frank. "It must be getting dark
outside." It had been dark from the beginning in the cave.

"Seven o'clock in the evening," went on Andy, "and we came in here
about four! The tide has several hours to rise yet, and----"

He did not finish, but he glanced down at the water that