Carter was ready with his blade for any encounter with man or beast that might come his way; and so he started off up the largest tunnel.

The perpetually burning radium light that had been set in the wall when the tunnel was constructed furnished sufficient illumination for the earthman to see his way quite clearly.

Carter halted before a massive door set into the end of a tunnel. It was inscribed with hieroglyphics unfamiliar to the earthman. The subdued drone of what sounded like many motors seemed to come from somewhere beyond the door.

He pushed open the unbarred door and halted just beyond, staring unbelievingly at the tremendous laboratory in which he found himself.

Great motors pumped oxygen through low pipes into rows of glass cages that lined the walls and filled the antiseptically white chamber from end to end. In the center of the laboratory were several operating tables with large searchlights focused down upon them from above.

But the contents of the glass cages immediately absorbed the earthman's attention.

Each cage contained a giant white ape, standing upright inside, apparently lifeless.

The top of each hairy head was swathed in bandages. If these beasts were dead, why then the oxygen tubes running to their cages?

Carter moved across the room to examine the cases at closer range. Halfway to the farther wall he came upon a low, glassed dome that covered a huge pit set in the floor.

He gasped. The pit was filled with dead bodies, red warriors with the tops of their heads neatly sliced off!

Far below, in the pit, John Carter could see forms moving in and about the bodies of the dead red men.

They were rats; and as he watched the earthman could see them dragging bodies off into adjoining tunnels. These tunnels probably entered the main one which ran into the rats' underground city.

So this was where the beasts got the skulls and bones with which they constructed their odorous, underground dwellings!

Carter's eyes scanned the laboratory. He noted the operating tables, the encased instruments above, the anesthetics. Everything pointed to some grisly experiment, conducted by some insane scientist.

Within a glass case were many books. One ponderous volume was inscribed in gold letters: PEW MOGEL, HIS LIFE AND WONDERFUL WORKS.

The earthman frowned. What was the explanation? Why this well-equipped laboratory buried in an ancient lost city, a city apparently deserted except for apes, rats, and a giant man?

Why the cases about the wall containing the mute, motionless bodies of apes with bandaged heads? And the red men in the pit-why were their skulls cut in half, their brains removed?

From whence came the giant, the monstrous creature whose likeness had existed only in the Barsoomian folklore?

One of the books in a case before Carter bore the name "Pew Mogel." What connection had Pew Mogel with all this and who was the man?

But more important, where was Dejah Thoris, the Princess of Helium?

John Carter reached for Pew Mogel's book. Suddenly the room fell silent. The generators that had been humming out their power, stopped.

"Touch not that book, John Carter," came the words echoing through the laboratory.

Carter's hand dropped to his sword. There was a moment's pause; then the hidden voice continued.

"Give yourself up, John Carter, or your princess dies." The words were apparently coming from a concealed loudspeaker somewhere in the room.

"Through the door to your right, earthman, the door to your right."

Carter immediately sensed a trap. He crossed to the door. Warily, he pushed it open with his foot.

Upon a gorgeous throne at the far end of a huge dome-shaped chamber sat a hideous, misshapen man. A tiny, bullet head squatted upon massive shoulders.

Everything about the creature seemed distorted. His torso was crooked, his arms were not equal in length; one foot was larger than the other.

The face in the diminutive head leered at John Carter. A thick tongue hung partly out over yellowed teeth.

The hulking body was encased in gorgeous trappings of platinum and diamonds. One claw-like hand stroked the bare head.

From head to foot there was apparently not a hair on his body.

At the man's feet crouched a great, four-armed shaggy brute-another white ape. Its little red eyes were fixed steadily upon the earthman as he stood at the far end of the chamber. The man on the throne idly fingered the microphone with which he had summoned Carter to the room.

"I have trapped you at last, John Carter!" Beady, cocked eyes glared with hatred. "You cannot cope with the great brain of Pew Mogel!"

Pew Mogel turned to a television screen studded with dials and lights of various colors.

His face twisted into a smile. "You honor my humble city, John Carter. It is with the greatest interest I have watched your progress through the many chambers of the palace with my television machine." Pew Mogel patted the machine.

"This little invention of my good teacher, Ras Thavas," continued Pew Mogel, "which I acquired from him, has been an invaluable aid to me in learning of your intended search for my unworthy person. It was unfortunate that you should suspect the honorable intentions of my agent that afternoon in the jeddak's chambers.

"Fortunately, however, he had already completed his mission; and through an extension upon this television set, concealed cleverly behind a mirror in the jeddak's private throne room, I was able to see and hear the entire proceedings."

Pew Mogel laughed vacantly, his little unblinking eyes staring steadily at Carter who remained motionless at the other end of the room.

The earthman could see nothing in the chamber that indicated a trap. The walls and floor were all of grey, polished ersite slabs. Carter stood at one end of a long aisle leading to Pew Mogel's throne.

Slowly he advanced toward Pew Mogel, his hand grasping his sword, the muscles of his arm etched bands of steel.

Halfway down the aisle, the earthman halted. "Where is Dejah Thoris?" His words cut the air.

The microcephalic head* of Pew Mogel cocked to one side. Carter waited for him to speak.

* A microcephalic head is one possessing a very small brain capacity. It is the opposite of megacephalic, which means a large brain capacity. Generally microcephalia is a sign of idiocy, although in the case of Pew Mogel, the condition did not mean idiocy, but extreme craftiness, and madness, which might indicate that, since Pew Mogel was an artificial, synthetic product of Ras Thavas, one of Mars's most famous scientists, his microcephalia was either caused by a disease, or by inability of the brain to adapt itself to a foreign ill-fitting cranial cavity. Pew Mogel's head was obviously too small for his body, or for his brain. Ed.

In spite of having the features of a man, Pew Mogel did not look quite human. There was something indescribably repulsive about him, the thin lips, the hollow cheeks, the close-set eyes.

Then Carter realized that those eyes were unblinking. There were no eyelids. The man's eyes could never close. Pew Mogel spoke coldly. "I am greatly indebted to you for this visit. I was fortunate enough to be able to entertain your princess and your best friend; but I hardly dared to hope you would honor me, too."

Carter's face was expressionless. Slowly he repeated, "Where is Dejah Thoris?"

Pew Mogel leered mockingly.

The earthman advanced toward the throne. The white ape at Pew Mogel's feet growled, the hairs on its neck bristling upright as Pew Mogel flinched slightly.

Again the twisted smile passed over his face as he raised his hand toward John Carter and drawled.

"Have patience, John Carter, and I will show you your princess; but first, perhaps you will be interested in seeing the man who, last night, told you to meet him at the main bridge outside the city."