hey came unexpectedly upon a huge rock that shut off the
passage and blocked them from proceeding a single step farther.

This rock was separate from the rest of the mountain and was in motion,
turning slowly around and around as if upon a pivot. When first they
came to it there was a solid wall before them; but presently it
revolved until there was exposed a wide, smooth path across it to the
other side. This appeared so unexpectedly that they were unprepared to
take advantage of it at first, and allowed the rocky wall to swing
around again before they had decided to pass over. But they knew now
that there was a means of escape and so waited patiently until the path
appeared for the second time.

The children and the Wizard rushed across the moving rock and sprang
into the passage beyond, landing safely though a little out of breath.
Jim the cab-horse came last, and the rocky wall almost caught him; for
just as he leaped to the floor of the further passage the wall swung
across it and a loose stone that the buggy wheels knocked against fell
into the narrow crack where the rock turned, and became wedged there.

They heard a crunching, grinding sound, a loud snap, and the turn-table
came to a stop with its broadest surface shutting off the path from
which they had come.

"Never mind," said Zeb, "we don't want to get back, anyhow."

"I'm not so sure of that," returned Dorothy. "The mother dragon may
come down and catch us here."

"It is possible," agreed the Wizard, "if this proves to be the path she
usually takes. But I have been examining this tunnel, and I do not see
any signs of so large a beast having passed through it."

"Then we're all right," said the girl, "for if the dragon went the
other way she can't poss'bly get to us now."

"Of course not, my dear. But there is another thing to consider. The
mother dragon probably knows the road to the earth's surface, and if
she went the other way then we have come the wrong way," said the
Wizard, thoughtfully.

"Dear me!" cried Dorothy. "That would be unlucky, wouldn't it?"

"Very. Unless this passage also leads to the top of the earth," said
Zeb. "For my part, if we manage to get out of here I'll be glad it
isn't the way the dragon goes."

"So will I," returned Dorothy. "It's enough to have your pedigree
flung in your face by those saucy dragonettes. No one knows what the
mother might do."

They now moved on again, creeping slowly up another stee