However, I was much interested in the work in the shops and did not mind much whether I went out or not.

Ever since I had seen Fal Sivas's wonder-craft and had listened to his explanation of the marvellous mechanical brain that controlled it, it had been constantly in my thoughts. I saw in it all the possibilities of power for good or evil that Fal Sivas had visualized, and I was intrigued by the thought of what the man who controlled it could accomplish.

If that man had the welfare of humanity at heart, his invention might prove a priceless boon to Barsoom; but I feared that Fal Sivas was too selfish and too mad for power to use his invention solely for the public good.

Such meditation naturally led me to wonder if another than Fal Sivas could control the brain. The speculation intrigued me, and I determined to ascertain at the first opportunity if the insensate thing would respond to my will.

That afternoon Fal Sivas was in his laboratory, and I was working in the shops with the poor manacled artisans. The great ship lay in the adjoining room. Now, I thought, presented as good a time as any to make my experiment.

The creatures in the room with me were all slaves. Furthermore, they hated Fal Sivas; so it made no difference to them what I did.

I had been kind to them and had even encouraged them to hope, though they could not believe that there was any hope. They had seen too many of their number die in their chains to permit them to entertain a thought of escape. They were apathetic in all matters, and I doubt that any of them noticed when I left the shop and entered the hangar where the ship rested upon its scaffolding.

Closing the door behind me, I approached the nose of the craft and focused my thoughts upon the brain within. I imparted to it the will to rise from its scaffolding as I had seen Fal Sivas cause it to do and then to settle down again in its place. I thought that if I could cause it to do that, I could cause it to do anything that Fal Sivas could.

I am not easily excited; but I must confess that my every nerve was tense as I watched that great thing above me, wondering if it would respond to those invisible thought-waves that I was projecting into it.

Concentrating thus upon this one thing naturally curtailed the other activities of my mind, but even so I had visions of what I might accomplish if my experiment proved successful.

I presume that I had been there but a moment, yet it seemed a long while; and then slowly the great craft rose as though lifted by an invisible hand. It hovered for a moment ten feet above its scaffolding, and then it settled down to rest again.

As it did so, I heard a noise behind me; and, turning quickly, I saw Fal Sivas standing in the doorway of the shop.