Free The Secret of the Caves by Franklin W. Dixon

then called out, “Hey, fellows, wait for me!”
    He took a step forward and stumbled. As he fell, he groped wildly for a firm rock, but there was nothing there.
    With a cry of terror Biff hurtled down into blackness.
    For a moment the other three boys froze in their tracks. Then they shouted for Biff, time and again, but there was no answer. They searched frantically among the rocks and crevices, but found no sign of him.
    In the glow of the flashlights they looked at one another anxiously and listened in vain for a faint cry. There was no sound but the echoes of their own voices.
    â€œWe won’t give up!” Frank vowed. “We’ll search every pit and hole in here!”
    With desperate patience they scoured the cave, but at last were forced to admit that it was no use.
    â€œThis place is too big,” Chet said dejectedly. “We need more light.” He sat down on a rock and buried his face in his hands.
    â€œI have an idea,” Frank offered. “Let’s build a fire. That’ll help.”
    Chet brightened. “Good idea!”
    â€œCome on,” Frank said. “We have lots of wood left in the outside cave.”
    â€œThat’s not a bad stunt!” Joe declared hopefully. “With a roaring bonfire we’ll be able to light up the whole place enough to see what we’re doing.”
    The boys retraced their steps into the outer cavern where they had slept. They filled their arms with wood and were about to re-enter the tunnel when Joe noticed something that made him drop his wood on the stone floor with a clatter.
    â€œWhat’s wrong?” Chet asked.
    â€œThat’s funny,” Joe returned. “I was sure we left our supplies right near this woodpile.”
    â€œWe did,” Frank assured him.
    Joe turned his flashlight on the place where the greater part of their supplies had been stacked. A loaf of bread and a tin of sardines lay on the rock, but that was all.
    â€œThey’ve been stolen!” Frank exclaimed.
    â€œBy that prowler, I’ll bet!” Joe said. “He probably hid himself until we passed, then sneaked back here and stole our food.”
    â€œWe can’t worry about that now,” Frank said grimly. “Let’s go!”
    Swiftly Joe gathered up his firewood and the boys returned to the big vault.
    Hastily the fire was built and soon the flames flared high. The companions were surprised at the number of holes and crevices now revealed.
    â€œIt’s a wonder we weren’t all killed,” Chet said. “We were prowling around this chamber without any idea of the real danger.”
    Methodically the boys resumed their search, investigating each opening, deep or shallow. But in spite of the extra light and all their shouting, their efforts were in vain.
    â€œI’m afraid it’s no use,” Chet said, gulping. “It’s as if Biff was swallowed up.”
    â€œWe need help,” Frank said tersely. “We’ll go to the village and get some men with ropes and searchlights.”
    Disconsolately the boys turned back. But as they did, Chet let out a bloodcurdling cry.
    On the wall of the cavern flickered the huge shadow of a hand!

CHAPTER XI
    No Trespassing!
    THE ghostly shadow caused the boys’ hearts to pound until they saw the reason for it. A hand was reaching up from one of the pits, and the bonfire’s glow threw its silhouette on the cavern wall.
    â€œBiff!” Joe cried out.
    Only a groan answered. The Hardys and Chet leaped toward the faltering hand as it groped for the lip of the pit. Frank grasped it and together the boys pulled Biff out. He lay dazed for a moment.
    â€œYou’re hurt!” said Joe, bending down to examine a large egg on Biff’s left temple.
    â€œI’m all right now. A little dizzy yet, but it isn’t serious.”
    â€œWhat happened?”
    â€œI fell into the pit and struck my head against the rocks. When I came to, I