haven't tried
before an' mebbe we'll run across 'em. If everything else fails, then
we'll turn out every man jack of the crew and go over every inch of the
island."

To the agonized father, everything that savored of delay seemed
intolerable, but he yielded to the wisdom of Tyke's suggestion and once
more they started out in their desperate search.

CHAPTER XXV

THE LAKE OF FIRE

Drew was all animation in an instant at the new hope that sprang up
within him with its offer of possible safety for his companion and
himself.

"Why didn't I think of it before?" he repeated, his voice shaken with
excitement.

"You didn't think of it before, because you were working like a slave.
No man can work like that and think of anything but what he is doing.
Oh, Allen, won't it be great if you are right?"

"I'm going to see if I am right," he replied.

"How can you tell?" she asked divining that he was fumbling at his
pocket.

"In this way," he answered, drawing out the oilskin bag that contained
his precious matches.

He struck a match and held it aloft.

At first the flame mounted straight up in the air. Then an instant
later it was deflected and stood out at a distinct angle from the stick.

"See," cried Allen jubilantly. "There's a current of air in the cave.
It's too slight for us to feel, but the flame feels it. If we were
sealed up utterly in the cave, the air would be still. Somewhere the
air is coming in from the outside world and it's up to us to find out
where."

"Thank God!" murmured Ruth tremulously.

In the sudden transition from despair to hope, they took little account
of the difficulties they might have to overcome before they reached
that other entrance--or the exit, from their point of view--which they
had reason to believe existed. But as their first jubilation subsided
somewhat, a soberer view began to thrust itself upon them.

Admitting that there was an exit, what guarantee had they of reaching
it? Suppose a fathomless gulf barred their way? Suppose the passage
narrowed to a point too small for them to thrust themselves through?
Suppose when the coveted exit should at last be found it should prove
to be in the ceiling of the cave instead of the side, and hopelessly
out of reach?

But they quickly dismissed these dismal forebodings. Those problems
could wait for solution until they faced them. The present at least
was illumined by hope.

"Come along, Ruth," cried Allen gaily