cavern to fetch the pistols manoeuvring so as
to be last, and as soon as the party had disappeared over the shelf he
gave a glance after them, and turned sharply.

"Foul air won't hurt me," he said; and he dived right in rapidly to
regain the pistols and cutlass, so as to have the laugh of his messmates
when they returned on board.

CHAPTER THIRTY THREE.

ANOTHER ALARM.

"It's all over," thought Don, as the man came on, with discovery
inevitable if he continued at his present rate. They were about fifty
feet from the entrance, and they felt that if they moved they would be
heard; and, as if urged by the same impulse, they stood fast, save that
Jem doubled his fist and drew back his arm ready to strike.

All at once the man stopped short.

"He sees us," said Don, mentally.

But he was wrong, for the sailor thrust his fingers into his mouth and
gave a shrill whistle, which ran echoing through the place in a
curiously hollow way.

"That's a rum un," he said, with a laugh. "Blow some o' the foul air
out. Wonder how far he went in?"

He walked on slowly, and then stopped short as if he saw the hiding
pair; but there was no gesture made, and of course his face was
invisible to the fugitives, to whom he seemed to be nothing but a black
figure.

"Plaguey dark!" ejaculated the man aloud.

_Hiss-s-s-s_!

A tremendously loud sibillation came out of the darkness--such a noise
as a mythical dragon might have made when a stranger had invaded his
home. The effect was instantaneous. The young sailor spun round and
darted back to the mouth of the cave, where he half lowered himself down
over the shelf facing toward the entry, and supporting himself with one
hand, shook his fist.

"You wait till I come back with a lanthorn!" he cried. "I'll just show
you. Don't you think I'm scared."

_Whos-s-s-s-s_ came that hissing again, in a loud deep tone this time,
and the sailor's head disappeared, for he dropped down and hastily
descended after his messmates, flushed and excited, but trying hard to
look perfectly unconcerned, and thoroughly determined to keep his own
counsel as to what he had heard, from a perfect faith in the effect of
the disclosure--to wit, that his companions would laugh at him.

Inside the cave Jem was leaning up against the wall, making strange
noises and lifting up first one foot and then the other. He seemed to
be suffering agonies, for he puffed and gasped.

"Jem, be quiet!" whispered Do