t came.

It was so dark that its motions were more those of a shadow than of some
living creature, and at last it seemed quite to die away among some
loose rocks, just where the gap ended in a precipice.

"Gone," said Sydney, drawing a long breath; "why, it was after the
provisions."

"Evidently. I couldn't have thought that there were any live creatures
here."

"Looked like a great monkey."

"Well, I thought so once--an ape, but it couldn't have been."

"I say," whispered Syd; "was it a man, and they're going to play some
prank on us from the ship to see if we are on the look-out?"

"What's that?" said a voice behind them, and the two lads started to
find that the lieutenant had come up to them unawares while they were
talking earnestly.

"We just saw something come up from that end of the gap, sir," said Syd;
"it was like a monkey."

"And Mr Belton here fancies it might be a spy from the _Sirius_ to see
if we were on the watch," said Roylance.

"Impossible! they would not play us such a trick. Stop, it might be
from the enemy--a boat landing men to see what we are about. But
where?" he said, excitedly. "They couldn't have landed where we did,
because there are two men on the watch, and I don't think there is any
other place. Let's see."

Orders were given, the men seized their arms, and after a few admonitory
words had been whispered, a search commenced, anything but an adequate
one, for the task was one of risk, and the men had to proceed with the
greatest caution, so as not to make a false step and go over the side,
either into the sea or down one of the cracks and rifts into which the
rock was cleft.

This went on for a couple of hours, during which the men on the watch
were certain that no one had landed, and at last the weary sailors felt
ready to endorse the remark of Terry, which somehow became spread among
them, that it was only a trick of the captain's son to set them on the
alert.

At last this came to the lieutenant's ears, and he called Syd and
Roylance aside.

"Was this some prank?" he said, sternly.

"I would not be guilty of such a trick, sir," said Syd, warmly. "It
would have been unfair to the men, who were tired, and an insult to you,
sir."

"Of course it would, gentlemen," said the lieutenant. "I beg your
pardon."

He went away, feeling rather uneasy, and set watches in two more places,
with orders to fire at the slightest alarm. Then in turn with Terry he
visited th