of footsteps. Mr.
Jenks started.

"They're coming back!" he whispered hoarsely. "Run!"

They all turned and sped toward their hiding place. But they were too
late. An instant later Folwell, Munson and the other diamond makers
confronted them. Our friends made a bold rush, but were caught before
they could go ten feet.

"We have them!" cried Munson. "They walked right into our hands!"

It was true. Tom Swift and the others were the prisoners of the diamond
makers.

CHAPTER XXIII--BROKEN BONDS

"Well," remarked Tom Swift, in mournful tones, "this looks as if we were
up against it; doesn't it?"

"Bless my umbrella, it certainly does," agreed Mr. Damon.

"And it's all my fault," said Mr. Jenks. "I shouldn't have gone into the
big cave. I might have known those men would come back any time."

The above conversation took place as our friends lay securely bound in
a small cave, or recess, opening from the larger cavern, where, about
an hour before, they had been captured and made prisoners by the diamond
makers. Despite their struggles they had been overpowered and bound,
being carried to the cave, where they were laid in a row on some old
bags.

"It certainly is a most unpleasant situation, to say the least,"
observed Mr. Parker.

"And all my fault," repeated Mr. Jenks.

"Oh, no it isn't," declared Tom Swift, quickly. "We were just as ready
to follow you into that cave as you were to go. No one could tell that
the men would return so soon. It's nobody's fault. It's just our bad
luck."

From where he lay, tied hand and foot, the young inventor could look
out into the cave where he and the others had been caught. The diamond
makers were busily engaged, apparently in getting ready to manufacture
another batch of the precious stones. They paid little attention to
their captives, save to warn them, when they had first been taken into
the little cave, that it was useless to try to escape.

"They needn't have told us that," observed Tom, as he and the others
were talking over their situation in low voices. "I don't believe any
one could loosen these ropes."

"They certainly are pretty tight," agreed Mr. Damon. "I've been tugging
and straining at mine for the last half hour, and all I've succeeded in
doing is to make the cords cut into my flesh."

"Better give it up," advised Mr. Jenks.

"We'll just have to wait."

"For what?" the scientist wanted to know.

"To see what they'll do with us. They can't k