"My brain was the greatest achievement of all The Master Mind's creations.

"For years I was a devoted pupil of Ras Thavas in his laboratories at Morbus. I learned all that the Master could teach me of the secrets of creating living tissue. When I learned from him all that I thought necessary to pursue my plans, I left Morbus. With a hundred synthetic men I escaped over the Great Toonolian Marshes on the backs of malagors, the birds of transport.

"I brought with me all the intricate equipment that I could steal from his laboratories. The rest, I have fashioned here in this ancient deserted city where we finally landed."

John Carter was studying Pew Mogel intently.

"I was tired of being a slave," continued Pew Mogel. "I wanted to rule; and by Issus, I have ruled; and some day I shall rule all Barsoom!"

Pew Mogel's eyes gleamed.

"It was not long before red men gathered in our city, escaped and exiled criminals. Since their faces would only lead them to capture and execution in other civilized cities on Barsoom, I persuaded them to allow me to transfer their brains into the bodies of the stupid white apes that overran this city.

"I promised to later restore their brains into the bodies of other red men, provided they would help me in my conquests."

Carter recalled the apes with the bandaged heads in the adjoining laboratory, and the red men with their skulls sliced off in the chamber of the rats. He began to understand a little; then he remembered Joog. "But the giant?" asked John Carter. "Whence came he?"

Pew Mogel was silent for a minute; then he spoke.

"Joog I have built, piece by piece, during several years, from the bones, tissues and organs of a thousand red men and white apes who came voluntarily to me or whom I captured.

"Even his brain is the synthesis of the brains of ten thousand red men and white apes. Into Joog's veins I have pumped a serum that makes all tissues self-repairing.

"My giant is practically indestructible. No bullet or cannon-shot made can stop him!"

Pew Mogel smiled and stroked his hairless chin. "Think how powerful my ape soldiers will be," he purred, "each one armed with the great strength of an ape. With their four arms they can hold twice as many weapons as ordinary men, and inside their skulls will function the cunning brains of human beings.

"With Joog and my army of white apes, I can go forth and become master of all Barsoom." Pew Mogel paused and then added, "provided I acquire more iron for even greater weapons than I already have."

Now Pew Mogel had risen from his throne in his great excitement.

"I preferred to conquer peacefully by first acquiring the Helium iron works as payment for Dejah Thoris's safe return. But the Jeddak and John Carter force me into other alternatives. However, I'll give you one more chance to settle peacefully," he said.

Pew Mogel's hand moved toward the right arm of his throne, as he pulled a duplicate lever. A beautiful woman swung into view.

It was Dejah Thoris!

At the sight of his princess chained to the other pillar before him John Carter grew very pale. He sprang forward to free her.

His earthly muscles could have easily covered the distance in one leap; but halfway there in his spring, Dejah Thoris and Tars Tarkas saw the earthman sprawl in mid-air as though he had struck full force against some invisible barrier. Half-stunned, he crumpled to the floor.

Dejah Thoris gave a little cry. Tars Tarkas strained at his bonds. Slowly, the earthman rose to his feet, shaking his body like some majestic animal. With his sword he reached down and felt the barrier that stood between him and the throne. Pew Mogel laughed harshly.

"You are trapped, John Carter. The invisible glass partition that you struck is another invention of the great Ras Thavas that I acquired. It is invulnerable.

"From there, you may watch the torture of your princess, unless she sees fit to sign a note to her father demanding the surrender of Helium to me."

The earthman looked at his princess not ten feet from him. Dejah Thoris held her head proudly high, which was answer enough to Pew Mogel's demands that she betray her people.

Pew Mogel saw, and angrily issued a command to the ape. The white brute rose and ambled over to Dejah Thoris. Grabbing her hair with one paw, he forced her head back until he could see her face. His hideous grinning face was not two inches from hers.

"Demand Helium's surrender," hissed Pew Mogel, "and you shall have your freedom!"

"Never!" the word shot back at him.

Pew Mogel flung another command to the ape.

The creature planted his great, pendulous lips on those of the princess. Dejah Thoris went limp in his embrace, while Tars Tarkas surged vainly at the steel chains. The girl had fainted.

The earthman again hurled himself futilely against the barrier that he could not see.

"Fool," yelled Pew Mogel, "I gave you your chance to retain your princess by turning over to me the Helium iron works; but you and the Jeddak thought you could thwart me and regain Dejah Thoris without paying me the price I asked for her safe return. For that mistake, you all die."

Pew Mogel again reached over to the instrument board beside his throne.