"All right," was the immediate response, and in a moment, as the rope swung over their heads, a heavy sound was heard beneath.
"It reaches the bottom," cried Guy joyfully. "The rope is slack."
He hauled on it eagerly, until ten yards or more lay in coils at his feet. Then it became taut. The bottom of the cliff was fifty feet below.
The roar of the water was now loud and fierce, but it lay more to one side. Directly beneath them was solid ground.
With a trembling hand Guy pulled at the hook and secured it to the ledge. Claiming the right to go first, he let himself over the verge, and a joyful hail announced that he had reached the bottom in safety.
Melton stuck his torch in a crevice of the rock and started after him. As his feet touched the ground Guy lit a fresh torch and the light revealed a level space of white sand, strewn with rocks.
Overhead was the glow of Melton's torch on the ledge, and far beyond on the dizzy summit of the cliff twinkled the light that the colonel held.
"We are on the bottom," shouted Guy, with all his might.
His voice echoed again and again through the cavern. A reply came back, but it was almost lost in the roar of the unseen waters.
With feelings that it would be difficult to describe they now advanced along the sand, bearing the torches high over their heads.