Another male then sprang into the arena and, repeating the horrid cries of his king, followed stealthily in his wake. Another and another followed in quick succession until the jungle reverberated with the now almost ceaseless notes of their bloodthirsty screams. It was the challenge and the hunt.

How plainly it all came back to the ape-man now as he heard the familiar beating of the drums in this far-off city!

As he ascended the steps farther he could see over the top of the castle wall below into the courtyard beyond. He saw a number of gorillas dancing to the booming of the drums. The scene was lit by torches, and as he watched, a fire was lighted near the dancers. The dry material of which it was built ignited quickly and blazed high, revealing the scene in the courtyard like daylight and illuminating the face of the cliff and the stairway that Tarzan was ascending; then it died down as quickly as it had arisen.

The ape-man hastened up the stone stairway that wound and zigzagged up the cliff face, hoping that no eye had discerned him during the brief illumination of the cliff. There was no indication that he had been discovered as he approached the grim pile now towering close above him, because the strange figure gazing down upon him from the ramparts of the castle gave no sign that might apprise the ape-man of its presence. Chuckling, it turned away and disappeared through an embrasure in a turret.

At the top of the stairway Tarzan found himself upon a broad terrace, the fore part of the great ledge upon which the castle was built. Before him rose the grim edifice without wall or moat looming menacingly in the darkness.

The only opening on the level of the ledge was a large double doorway, one of the doors of which stood slightly ajar. Perhaps the lord of the jungle should have been warned by this easy accessibility. Perhaps it did arouse his suspicions—the natural suspicion of the wild thing for the trap—but he had come here for the purpose of entering this building; and he could not ignore such a God-given opportunity.

Cautiously he approached the doorway. Beyond was only darkness. He pushed against the great door, and it swung silently inward. He was glad that the hinges had not creaked. He paused a moment in the opening, listening. From within came the scent of gorillas and a strange man-like scent that intrigued and troubled him, but he neither heard nor saw signs of life beyond the doorway.

As his eyes became accustomed to the gloom of the interior he saw that he was in a semi-circular foyer in the posterior wall of which were set several doors. Approaching the door farthest to the left he tried it; but it was locked, nor could he open the second. The third, however, swung in as he pushed upon it, revealing a descending staircase.

He listened intently but heard nothing; then he tried the fourth door. It too was locked. So were the fifth and sixth. This was the last door, and he returned to the third. Passing through it he descended the stairway, feeling his way through the darkness.

Still all was silence. Not a sound had come to his ears since he had entered the building to suggest that there was another within it than himself; yet he knew that there were living creatures there. His sensitive nostrils had told him that and the strange, uncanny instinct of the jungle beast.