, or whatever it was, is hiding in that,"
he added jestingly. "At any rate I'm going to take a minute and see
what it is."

He made a step in the direction he had indicated. Ruth sought to
restrain him.

"Don't you think you had better call my father and Mr. Grimshaw before
you venture in there?" she asked. "You don't know what may be lurking
there."

"Nonsense," laughed the man lightly. "They'd only be vexed at being
interrupted in their digging. At any rate they're within easy call--if
there should be any need of them."

Ruth was silenced though only half convinced. Together they went over
to a gaping rent in the side of the hill.

As a matter of precaution, Drew had taken his revolver from his belt
and held it ready in his hand. He had really no expectation of meeting
anything hostile in human shape and he did not believe that any animal
that would be at all formidable ranged the island.

"If it's a ghost, I don't suppose this revolver would do any good," he
joked, more to relieve Ruth's uneasiness than any that he felt himself.
"At the very least I'd have to have a silver bullet or one that had
been dipped in the river Jordan."

The opening before which they stood was irregular in shape and seemed
to have been made by one of the convulsions of nature that apparently
were so common to the island. It was, roughly speaking, about four
feet wide and nine high, and from the glimpse they got into its depths
seemed to widen out in the interior. There was nothing about it to
speak of human occupancy and the ground leading to it bore no marks of
footprints. Nor were there any bones scattered about that might
indicate that it was the lair of wild beasts.

Drew cupped his hands to his mouth and sent forth a ringing call.

"Hello, in there!" he shouted.

There was no answer, but the reverberations of his own voice that came
back to him seemed to show that the cave extended inward to a
considerable depth.

"Hello!" he shouted again. "If there's any one in there, come out!
We're friends and won't hurt you."

Again there was no answer.

"Doesn't seem to be sociably inclined," muttered Allen grimly.

"I guess there's nobody there," said Ruth. "Let's go back to the
others, Allen. We've spent too much time already on this foolish
notion of mine."

"It wasn't foolish at all," protested Drew. "As a matter of fact it
may prove to be of the greatest importance. We ought to sift the
matter to the bottom