I soon found what was wrong with it and how it might be improved. Fal Sivas was delighted. He immediately recognized the value of the points I had made.

"Come with me," he said; "we will start work on these changes at once."

He led me to a door at one end of the hangar and, throwing it open, followed me into the room beyond.

Here, and in a series of adjoining rooms, I saw the most marvellously equipped mechanical and electrical shops that I have ever seen; and I saw something else, something that made me shudder as I considered the malignity of this man's abnormal obsession for secrecy in the development of his inventions.

The shops were well manned by mechanics, and every one of them was manacled to his bench or to his machine. Their complexions were pasty from long confinement, and in their eyes was the hopelessness of despair.

Fal Sivas must have noted the expression upon my face; for he said quite suddenly, and apropos of nothing else than my own thoughts, "I have to do it, Vandor; I cannot take the risk of one of them escaping and revealing my secrets to the world before I am ready."

"And when will that time come?" I asked.

"Never," he exclaimed, with a snarl. "When Fal Sivas dies, his secrets die with him. While he lives, they will make him the most powerful man in the universe. Why, even John Carter, Warlord of Mars, will have to bend the knee to Fal Sivas."

"And these poor devils, then, will remain here all their lives?" I asked.

"They should be proud and happy," he said, "for are they not dedicating themselves to the most glorious achievement that the mind of man has ever conceived?"

"There is nothing, Fal Sivas, more glorious than freedom," I told him.

"Keep your silly sentimentalism to yourself," he snapped. "There is no place for sentiment in the house of Fal Sivas. If you are to be of value to me, you must think only of the goal, forgetting the means whereby we attain it."

Well, I saw that I could accomplish nothing for myself or his poor victims by antagonizing him, and so I deferred with a shrug. "Of course, you are right, Fal Sivas," I agreed.

"That is better," he said, and then he called a foreman and together we explained the changes that were to be made in the motor.

As we turned away and left the chamber, Fal Sivas sighed. "Ah," he said, "if I could but produce my mechanical brain in quantities. I could do away with all these stupid humans. One brain in each room could perform all the operations that it now takes from five to twenty men to perform and perform them better, too—much better."

Fal Sivas went to his laboratory on the same level then, and told me that he would not require me for a while but that I should remain in my quarters and keep the door open, seeing that no unauthorized person passed along the corridor toward the ramp leading to his laboratories.