"Why don't they come back?"
"What keeps them so long?"
"I declare this waiting is worse than----"
"Doing nothing," Cora finished for Bess. "Probably the boys can't find
the kind of chocolates you ordered, pretty little plump maid, and
they're afraid to come back without them."
"Silly," protested Bess.
"But they are a long time," said Hazel, she and Belle having uttered the
two rather impatient sentences at the opening of this chapter.
The girls were in the bungalow, eating, not exactly bread and honey, but
ice cream and cake, which Mrs. Floyd had made. And they were talking of
the absence of Jack and his chums, who had gone to town to telephone to
Mr. Haight.
It was now lunch time and the girls, after waiting in vain for the boys,
had eaten, and were enjoying their dessert. Or rather, they were trying
to enjoy it under the rather unappetizing influence of impatient worry.
"If they don't come back pretty soon I'm going down there myself and see
if we can discover anything," Cora declared.
"Down where?" asked Belle.
"In the passage, of course. I want to see if we can find where that
queer noise came from."
"And who upset the furniture," added Bess.
"Well, we're on the track of it," said Hazel. "We are pretty certain,
now, that whoever did it came up through that sliding door, and went
down the same way. That accounts for our never seeing any one enter or
leave the bungalow after the manifestations, and that's why, after the
boys ran over so promptly the time we saw the dancing light, they
couldn't find any one. Whoever it was just slipped down through the
secret passage, pulled the section of flooring back into place, and
there was no trace."
"But where did they go after they got down in the passage?" asked Belle.
"They couldn't stay there all the while, and there's no sign of any one
there now, unless they're invisible. They couldn't get past the blocking
cement wall."
"There's something beyond that wall, and we're going to find it!"
declared Cora.
"Perhaps when the boys come back they won't have permission to tear it
down," suggested Bess.
"Then we'll begin our investigations from the other end," Cora said.
"What other end?" Hazel questioned.
"The cave! I think this passage connects with the cave. That would
explain a hiding place for whoever has been playing these tricks on us,
and making that strange noise."
"You mean the cave you accidentally discovered yesterday?" asked Belle.
"Yes," Cora answered. "I'm sure that has something to do with the
mystery. So if Mr. Haight won't let us open the wall, we may be able to
see what is on the other side by going to the cave, and finding the
passage that connects with the one which comes out into our bungalow."
"In that event the stone wall must be movable," suggested Hazel.
Cora jumped up so suddenly that she disturbed Bess who was leaning
against her.
"That's it! That's it!" Cora cried. "I wonder we didn't think of it
before. That surely is it!"
"What is?" eagerly demanded Belle. "You are talking in riddles."
"This whole affair is a riddle, girls!" exclaimed Cora. "But what Hazel
said gave me an idea. That cement wall seems solid, but it can't be. If
it were no one could pass. So it must be made to look solid to deceive
those not in the secret. Probably it is a balanced stone like the ones
you read of in stories of the cave dwellers. Some of them closed the
entrances to their caves by heavy rocks, set on pivots, turning when you
pressed on a certain mechanism. There are counterweights, just as in a
window, which makes the heaviest rock move easily. I'm sure that's what
is in the passage--a balanced rock doorway. And there won't be any need
of tearing the wall down at all!"
"It sounds like a detective story," commented Bess.
"It may turn out to be one before we're through," Cora said.
"Oh, dear! Why don't those boys hurry back?" cried Belle for perhaps the
tenth time. "Let's go out and look down the road to see if they are
coming."
The girls went out, too anxious and too eager to sit still, but they had
no sight of Jack and his chums.
"I'm not going to wait any longer!" exclaimed Cora at length. "If I'm
right, there will be no need of tearing down the wall. That is, if I can
find the mechanism that turns the rocky door. And if I'm wrong, there
won't be any harm in doing it."
"Doing what?" asked Bess.
"Going down into the passage to see what we can discover. Will you
come?"
"I will!" exclaimed Hazel.
"Then we will, too, Belle," said Bess, quickly. "They shan't call us
cowards, even if we are twins."
"Come on," cried Cora gaily. "We must do something or fly to pieces with
nerves. Anything is better than sitting still, waiting."
Back to the bungalow the girls hastened. The hole in the floor was still
open, the sliding door having been braced back so it could not be closed
by any accident.
"We don't want to go down there and not be able to get up again," Cora
remarked.
"Shall we tell Mrs. Floyd we're going to see what we can find?"
suggested Belle.
"No," decided Cora, after a moment's thought. "She might not want us to
until we have Mr. Haight's permission. We'll just do this on our own
responsibility. We won't damage the wall any."
Down the cement steps went the four girls, into the dark passage. The
boys had left behind their flashlights and these were carried by Cora
and Hazel. The small, but powerful lamps gave a good light.
"Ugh! It's rather creepy in here," complained Belle, looking back over
her shoulder.
"Don't be silly!" said Cora, sharply. "Just think of it! We may solve
the mystery all by ourselves."
"Let us hope so," murmured Bess.
They came to the cement wall that barred further progress along the
passage.
"First to see if it's solid rock," Cora suggested.
"How?" asked Belle.
"By tapping. I brought along a hammer." With this implement Cora gave
several blows against the obstruction. An unmistakable hollow sound
resulted.
"I believe it's only a wooden door, covered over with cement stucco,"
Cora said. "Now to find the secret catch."
With their flash lamps the girls went over every inch of the surface of
the door. At first it all looked alike, dull, gray, smooth cement. Then
Cora's light lingered a moment on a certain place.
"Girls, watch!" she said suddenly.
With her thumb she pressed on the spot where it seemed the cement was
worn smoother than elsewhere. And then, to the surprise of even Cora
herself, the cement door swung slowly back, revealing a dark passage
beyond.
"We've discovered it!" cried Cora. "No need to tear the door down. Just
as I suspected, it's on hinges. Come on, girls!"
Hardly realizing what they were doing, the others followed, their
torches illuminating the plank sides of the underground tunnel.
"Are you sure this is all right, Cora?" asked Belle, as she stepped
beyond the open door.
"I'm not sure anything is right about all this mystery," was the answer,
"but this is a chance we mustn't miss. Come on."
"But where are we going?" Belle queried.
"I can't tell, but I think to the cave," Cora answered. "Don't be
afraid. There's no danger."
Hardly had she spoken than a noise sounded behind them.
"Oh! what's that?" cried Belle, rushing forward.
"It sounded like a door closing," said Hazel.
She flashed her light back on the way they had come, and as she did so
she cried:
"It was the door. It has swung shut, girls! We're trapped!"