"We'll get away somehow--and make it good and hot for them in the
bargain," answered Tom, and his father nodded in approval.

With their thoughts on the _Rainbow_ and those on board, the
treasure hunters went back to the vicinity of the shattered cave.
Nobody felt much like working, yet to remain idle made the time hang
heavily on their hands.

"There is no use of our going to work in a haphazard fashion," were Mr.
Rover's words. "We must first go over the ground carefully and plan out
just what is best to do. Otherwise a good portion of our energies will
be wasted."

This was sound advice and was followed out. They surveyed the whole
vicinity with care, poking in among the rocks with long sticks, and
turning over such as were loose and easily moved.

"This looks as if it was going to be a long-winded job," was Sam's
comment, and he heaved a sigh. "I thought we'd come here, march into
the cave, and put our hands right on the gold and diamonds!"

Dick was a short distance away, poking into a hole with a stick. The
stick was over eight feet long, but the end did not appear to touch
anything.

"There is some kind of a hollow below here," he said to the others. "I
think we ought to investigate and see how large it is."

The others agreed with him, and all set to work to pull aside half a
dozen rocks which were in the way. They had to use all their strength
and even then the largest of the stones refused to budge.

"Let us get a small tree and use it for a pry," suggested Mr. Rover.

They had an ax with them, and Tom cut down the tree and trimmed it.
Then, resting the log on one stone, they inserted the end under the big
rock and pressed down with all their might.

"She's coming!" shouted Sam, as the big stone commenced to move.

"Yes, and look at the opening underneath," added Dick. "It must surely
be part of the cave!"

The sight of the big hole made all eager to know if it was really a
portion of the shattered cave and they worked on the big rock with
renewed energy. Twice it slipped back on them, but then they got a new
purchase and over it went and rolled out of the way. Then all of the
treasure hunters got on their hands and knees to gaze down into the
hole.

"It must be part of the cave," said Mr. Rover.

"I'll climb down on the rope," said Tom. "Hurry up, I can't wait!"

"You be careful, Tom, or you'll get hurt," warned his father. But it
must be confessed he was as eager as his son to learn whe