Frank reached the end of the ledge. The flashlight was clutched in his hand. Slowly he rose to his feet. But a small pebble betrayed him. He lost his balance and staggered for a second.
Had it not been for the flashlight the emergency would have passed because he flung out his hand and supported himself against the wall of the cave. But the heavy flashlight struck a loose projection of rock.
There was a grinding clatter of stone as the rock came free.
In the dead silence of the cave the noise seemed magnified many times. Frank knew that the sleepers would be aroused. He threw caution to the winds.
He leaped forward, gaining the entrance at a bound. Chet Morton and Biff Hooper, seeing that nothing was to be gained by further caution, scrambled to their feet and raced in pursuit.
The noise of the dislodged rock had already wakened one of the men. He raised himself on elbow in alarm and peered about. Then he saw the fleeing figures in the mouth of the cave and heard the running footsteps.
He sprang at once to his feet.
"They're getting away!" he roared. "Wake up, men! They're getting away!"
Instantly pandemonium prevailed within the
