He began to turn several dials, and Carter heard a strange, droning noise that increased steadily in volume.

Suddenly the earthman turned and raced for the door through which he came.

But before he had covered fifteen feet, another barrier had closed down. Escape through the door was impossible.

There was a window over on the wall to his right. He leaped for it. He struck another glass barrier.

There was another window on the left side of the room. He had nearly reached it when he was met by another wall of invisible glass.

In a flash he became acutely conscious of his predicament. The walls were moving in upon him. He could see now that the glass barriers had moved out from cleverly concealed slits in the adjoining walls.

The two side barriers, however, were fastened to horizontal pistons in the ceiling. These pistons were moving together, bringing the glass walls toward each other, and would eventually crush the earthman between them. Upon John Carter's finger was a jeweled ring. Set in the center of the ring was a large diamond. Diamonds can cut glass!

Here was a new type of glass, but the chances were it was not as hard as the diamond on Carter's finger!

The earthman clenched his fist, pressed the diamond ring against the barrier in front of him and quickly made a large circular scratch in the glass surface.

Then he crashed his body with all his strength against the area of glass enclosed by the scratch.

The section broke out neatly at the blow, and the earthman found himself face to face with Pew Mogel.

Dejah Thoris had regained consciousness, a set, intent expression on her beautiful face. A grim smile had settled over Tars Tarkas's lips when he saw that his friend was no longer impeded by the invisible barriers.

Pew Mogel shrank back on his throne and gasped in a cracked voice.

"Seize him, Gore, seize him!" Little beads of sweat stood forth on his brow.

Gore, the white ape, released his hold on Dejah Thoris and, turning, saw the earthman advancing toward them. Gore snarled viciously, revealing jagged, mighty fangs. He crouched low, so that his four massive fists supported his weight on the floor. His little, beady, blood-shot eyes gleamed hatred, for Gore hated all men save Pew Mogel.

Chapter 7 THE FLYING TERROR

As Gore, the great white ape with a man's brain, crouched to meet John Carter, he was fully confident of overcoming his puny man opponent.

But to make assurance doubly sure, Gore drew the great blade at his side and rushed madly at his foe, hacking and cutting viciously.

The momentum of the brute's attack forced Carter backward a few steps as he deftly warded off the mighty blows.

But the earthman saw his chance. Quickly, surely, his blade streaked. There was a sudden twist and Gore's sword went hurtling across the room. Gore, however, reacted with lightning speed. With his four huge hands he grasped the naked steel of the earthman's sword.

Violently he jerked the blade from Carter's grasp and, raising it overhead, snapped the strong steel in two as if it had been a splinter of wood.

Now, with a low growl, Gore closed in; and Carter crouched.

Suddenly the man leaped over the ape's head; but again with uncanny speed the monster shot out a hairy hand and grasped the earthman's ankle.

Gore held John Carter in his four hands, drawing the man closer and closer to the drooling jowls and gleaming fangs.

But with a surge of his mighty muscles, the earthman jerked free his arm and sent a terrific blow crashing full into Gore's face.

The ape recoiled, dropping John Carter, and staggered back toward the huge window on the right wall by Pew Mogel's throne.

Here the beast tottered; and the earthman, seeing his chance, once again leaped into the air, but this time flew feet foremost toward the ape.

At the moment of contact with the ape's chest, Carter extended his legs violently; and so, as his feet struck Gore, this force was added to the hurtling momentum of his body.

With a bellowing cry, Gore hurtled out through the window and his screams ended only when he landed with a sickening crunch in the courtyard far below.

Dejah Thoris and Tars Tarkas, chained to the pillars, had watched the short fight, fascinated by the earthman's sure, quick actions.

But when Carter did not succumb instantly to Gore's attack, Pew Mogel had grown frightened. He began jerking dials and switches; and then spoke swiftly into the little microphone beside him.

So now, as the earthman regained his feet and advanced slowly toward Pew Mogel, he did not see the black shadow that obscured the window behind him.

Only when Dejah Thoris screamed a warning did the earthman turn. But he was too late!

A giant hand, fully three feet across, closed about his body. He was lifted from the floor and pulled out quickly through the window.

To Carter's ears came the hopeless cry of his princess mingled with the cruel, hollow laugh of Pew Mogel.

Carter did not need the added assurance of his eyes to know that he was being held in the grasp of Pew Mogel's synthetic giant. Joog's fetid breath blasting across his face was ample evidence.

Joog held Carter several feet from his face and contracted his features in the semblance of a grin, exposing his two great rows of cracked, stained teeth the size of sharp boulders. Hoarse, gurgling sounds emanated from Joog's throat as he held the earthman before his face.

"I, Joog. I, Joog," the monster finally managed. "I can kill! I can kill!"

Then he shook his victim until the man's teeth rattled. But quite suddenly the giant was quiet, listening; then Carter became aware of muffled words coming, apparently, from Joog's ear.

Then John Carter realized that the command was coming from Pew Mogel, transmitted by short wave to a receiving device attached to one of Joog's ears.

"To the arena," repeated the voice. "Fasten him over the pit!"

The pit-what new form of devilish torture was this? Carter tried vaguely to ease the awful pressure that was crushing him. But his arms were pinned to his sides by the giant's grasp. All the man could do was breathe laboriously and hope that Joog's great strides would soon bring them to his destination, whatever that might be.

The giant's tremendous pace, stepping over tall, ancient edifices or across wide, spacious plazas in single, mighty strides, soon brought them to a large, crowded amphitheatre on the outskirts of the city.

The amphitheatre apparently was fashioned from a natural crater. Row upon row of circular tiers had been carved within the inner wall of the crater, forming a series of levels upon which sat thousands of white apes.

In the center of the arena was a circular pit about fifty feet across. The pit contained what appeared to be water whose level was about fifteen feet from the top of the pit.

Three iron-barred cages hung suspended over the center of the pit by means of three heavy ropes, one attached to the top of each cage and running up through a pulley in the scaffolding built overhead and down to the edge of the pit where it was anchored. Joog climbed partly over the edge of the coliseum and deposited Carter on the brink of the pit. Five great apes held him there while another ape lowered one of the cages to ground level.

Then he reached out with a hooked pole and swung the cage over the edge. He unlocked the cage door with a large key.

The keeper for the key was a short, heavy-set ape with a bull neck and exceedingly close-set eyes.

This brute now came up to Carter and although the captive was being held by five other apes, he grabbed him cruelly by the hair and jerked Carter into the cage, at the same time kicking him viciously.

The cage door was slammed immediately, it's padlock bolted closed.