John Carter found himself looking into a monstrous face. From top of shaggy head to bottom of its hairy chin, the head measured fully fifteen feet.

A new monstrosity had come to life on Mars. Judging by the adjacent buildings, the creature must have been a hundred and thirty feet tall!

The giant raised Carter high over his head and shook him; then he threw back his face. Hideous, hollow laughter rumbled out of his pendulous lips revealing teeth like small mountain crags.

He was dressed in an ill-fitting, baggy tunic that came down in loose folds over his hips but which allowed his arms and legs to be free.

With his other hand he beat his mighty chest.

"I, Joog. I, Joog," he kept repeating as he continued to laugh and shake his helpless victim. "I can kill! I can kill!" Joog, the giant, commenced to walk. Carefully he stepped along the barren streets, sometimes going around a building that was too high to step over. Finally he stopped before a partially ruined palace. The ravages of time had only dimmed its beauty. Huge masses of moss and vines trailed through the masonry, hiding the shattered battlements. With a sudden thrust, Joog, the giant, shoved John Carter through a high window in the palace tower.

When Carter felt the giant's hold releasing upon him he relaxed completely. He hit the stone floor in a long roll, protecting his head with his arms. As he lay in the deep darkness of the place where he had fallen, the earthman listened while he regained his breath.

No sound came to his ears for some time; then he began to hear the heavy breathing of Joog outside his window. Once more Carter's earthly muscles, reacting to the lesser gravity of Mars, sent him leaping twenty feet to the sill of the narrow window. Here he clung and looked once again into the hairy, hideous face of the giant.

"I, Joog. I, Joog," he mumbled. "I can kill! I can kill!" The giant's breath swept over Carter like a blast from a sulphur furnace. There would be no escape from that window!

Once more he dropped down into his cell. This time he commenced a slow circuit of the room, groping his way along the polished ersite slabs that formed the wall. The cobblestone floor was thick with debris. Once, Carter heard the sinister hiss of a Martian spider as he brushed its web.

How long he groped his way around the walls, there was no way of knowing. It seemed hours. Then, suddenly, the deathly silence was shattered by a woman's scream coming from somewhere in the building.

John Carter could feel his skin grew cold. Could that have been the voice of Dejah Thoris?

Once again John Carter leaped toward the faint light that marked the window ledge. Cautiously, he looked down. Joog lay on his back on the flagstones below, breathing as though he were asleep, his great chest rising five feet with every breath. Quietly he started to edge his way along a ledge that ran from the window and disappeared into the shadow of an adjoining tower. If he could make that shadow without awakening Joog!

He had almost gained his objective when Joog growled hoarsely.

He had opened one great eye. Now he reached up and, grabbing Carter by the leg, hurled him into the tower window again.

Wearily, the earthman crawled to the wall of his dark cell and there slumped down against it. That scream haunted his memory. He was tormented by the thought that Dejah Thoris might be in danger.

And where was Tars Tarkas? Pew Mogel must have captured him, too. Carter suddenly sprang to his feet.

One of the ersite slabs at his back had moved! He waited. Nothing came out. Cautiously, he approached the rock and shoved it with his foot. The slab moved slightly inward. Now Carter shoved the stone with all his tremendous strength. Inch by inch he moved it until finally there was room for him to squeeze his body through.

He was still in utter darkness, but his gripping fingers revealed to him that he was in a corridor between two walls. Perhaps this was the way out of his prison!

Carefully he shoved the stone back into position, leaving no trace of his disappearance from the room. The corridor in which he found himself was so low that he was forced to crawl on hands and knees. The low corridor had the stench of age, as if it had been unused for a long time.

Gradually the tunnel sloped more and more downward. Many little side-passages branched off from the main tunnel. There was no light, no noise. Only a faint, pungent odor beginning to fill the air.

Now it was growing lighter. The earthman realized that he must be in the subterranean caverns of the palace. The dim light was caused by the phosphorescent radium glow that is used on all Mars for radiation.

The source of this faint light the earthman suddenly discovered. It was shining through a cleft in the wall ahead. Pushing aside another loose stone, John Carter crawled forth into a chamber. He drew in his breath sharply.

Facing him was a warrior with drawn sword, the point of which was almost touching the breast of the earthman! John Carter leaped back with the speed of lightning, whipped out his own sword and struck at the other's weapon.

The arm of the red man fell from his body to the floor where it dissolved into dust. The ancient sword clattered on the cobblestones.

Carter could see now that the warrior had been leaning against the wall, balanced there precariously for ages, his sword arm extending in front of him just as it had stiffened long ago in death. The loss of the arm overbalanced the torso which toppled to the floor and there dissolved into a heap of ash-like dust!

In an adjoining chamber there were a score of women, beautiful girls, chained together by collars of gold around their necks. They sat at a table where they had been eating, and the food was still before them. They had been the prisoners, the slaves of the rulers of the long-dead city. The dry, motionless air combined with some gaseous secretion from the walls and dungeons had preserved their beauty through the ages.

The earthman had traversed some little distance down a musty corridor when he became aware of something scraping behind him. Whirling into a side corridor he looked back. Gleaming eyes were coming toward him. They followed him as he backed into the tunnel.

Now again came the scraping, repeated this time farther ahead in the tunnel. Other eyes shone ahead of him.

John Carter ran forward, his sword-point extended. The eyes ahead retreated, but those in back of him started to close.

It was very dark now, but far ahead the earthman could see a faint gleam of light filtering into the tunnel.

He ran toward the light. Fighting the things where he could see them would be a lot easier than stumbling around in a dark corridor.

Carter entered the room and in the dim light came face to face with the creature whose eyes he had seen ahead of him in the tunnel It was a species of the huge three-legged Martian rat!

Its yellow fangs were bared hideously in a vicious snarl, as it backed slowly away from Carter to the far end of the small room.

Now behind him came the other rat, and together the two beasts started to close in upon the earthman.

Carter smiled grimly as he gripped his sword. "I am the proverbial cornered rat now," he muttered as he swung his blade at the nearest creature.

It ducked the blow and scurried toward him.

But the earthman's sword was ready. The charging rat lunged full upon the waiting sword-point.

The momentum of the beast carried Carter back five feet; but he still retained a hold on his sword, the point of which had plunged through the animal's single shoulder and pierced its wild heart.

When Carter had jerked free his sword and turned to meet his other antagonist an exclamation of dismay escaped his lips. The room was half filled with rats!