"You were about right in assuming that an inhabitant of Thuria, if such exists, if he were of the same proportion to Thuria as you are to Barsoom, would be about eight sofs tall; and consequently, if my theory is correct, and I have no reason to doubt it, were you to travel from Barsoom to Thuria you would be but eight sofs tall when you reached the surface of the moon."

"Preposterous!" I exclaimed.

He flushed angrily. "You are nothing but an ignorant assassin," he cried. "How dare you question the knowledge of Fal Sivas? But enough of this; return to your quarters. I must get on with my work."

"I am going to Thuria," I said; "and if you won't go with me, I shall go alone."

He had turned back to enter his little laboratory, but I had followed him and was close behind him.

"Go away from here," he said; "keep out, or I will have you killed."

Just then I heard a cry from the room behind him, and a woman's voice calling, "Vandor! Vandor, save me!"

Fal Sivas went livid and tried to dash into the room and close the door in my face, but I was too quick for him. I leaped to the door and pushed him aside as I stepped in.

A terrible sight met my eyes. On marble slabs, raised about four feet from the floor, several women were securely strapped, so that they could not move a limb or raise their heads. There were four of them. Portions of the skulls of three had been removed, but they were still conscious. I could see their frightened, horrified eyes turn toward us.

I turned upon Fal Sivas. "What is the meaning of this?" I cried. "What hellish business are you up to?"

"Get out! Get out!" he screamed. "How dare you invade the holy precincts of science? Who are you, dog, worm, to question what Fal Sivas does; to interfere with the work of a brain the magnitude of which you cannot conceive? Get out! Get out! or I will have you killed."

"And who will kill me?" I demanded. "Put these poor creatures out of their misery, and then I will attend to you."

So great was either his rage or his terror, or both, that he trembled all over like a man with the palsy; and then, before I could stop him, he turned and darted from the room.

I knew that he had gone for help; that presently I should probably have all the inmates of his hellish abode upon me.

I might have pursued him, but I was afraid that something might happen here while I was gone, and so I turned back to the girl on the fourth slab. It was Zanda.

I stepped quickly to her side. I saw that she had not yet been subjected to Fal Sivas's horrid operation, and drawing my dagger I cut the bonds that held her.

She slipped from the table and threw her arms about my neck. "Oh, Vandor, Vandor," she cried, "now we must both die. They come! I hear them."