I can assure you that I was greatly mystified, but still more so by the events immediately following. Phor Tak seized the handle of the paint brush and made a pass a few inches above the metal torpedo. Instantly a portion of the torpedo, about an inch wide and three or four inches long, disappeared. Pass after pass he made until finally the whole surface of the torpedo had disappeared. Where it had rested the bench was empty. Phor Tak returned the handle of the paint brush to its floating position just above the floating jar rim and then he turned to us with an expression of child-like pride upon his face, as much to say, "Well, what do you think of that? Am I not wonderful?" And I was certainly forced to concede that it was wonderful and that I was entirely baffled and mystified by what I had seen.
"There, Nur An," exclaimed Phor Tak, "is the answer to your criticism of The Flying Death."
"I do not understand," said Nur An with a puzzled expression upon his face.
"Heigh-oo!" cried Phor Tak. "Have you not seen me render the device invisible?"
"But it is gone," said Nur An.
Phor Tak laughed his high cackling laugh. "It is still there," he said, "but you cannot see it. Here," and he took Nur An's hand and guided it toward the spot where the device had been.
I could see Nur An's fingers apparently feeling over the surface of something several inches above the top of the table. "By my first ancestor, it is still there!" he exclaimed.
"It is wonderful," I exclaimed. "You did not even touch it; you merely made passes above it with the handle of a paint brush and it disappeared."
"But I did touch it," insisted Phor Tak. "The brush was there, but you did not see it because it was covered by the substance which renders The Flying Death invisible. Notice this transparent glass receptacle in which I keep the compound of invisibility and all that you can see of it is that part of the rim which, by chance, has not been coated with the compound."
"Marvelous!" I exclaimed. "Even now, although I have witnessed it with my own eyes I can scarce conceive of the possibility of such a miracle."
"It is no miracle," said Phor Tak. "It is merely the application of scientific principles well known to me for hundreds of years. Nothing moves in straight lines; light, vision, electromagnetic forces follow lines that curve. The compound of invisibility merely bows outward the reflected light, which, entering our eyes and impinging upon our optic nerves, results in the phenomenon which we call vision, so that they pass around any object which is coated with the compound. When I first started to apply the compound to The Flying Death, your line of vision was deflected around the small portions so coated, but when I coated the entire surface of the torpedo, the curve of your vision passed completely around it on both sides so that you could plainly see the bench upon which it was resting precisely as though the device had not been there."
I was astounded at the apparent simplicity of the explanation, and, naturally, being a soldier, I saw the tremendous advantage that the possession of these two scientific secrets would impart to the nation which controlled them. For the safety; yes, for the very existence of Helium, I must possess them and if that were impossible, then Phor Tak must be destroyed before the secret of this infernal power could be passed on to any other nation. Perhaps I could so ingratiate myself with old Phor Tak as to be able to persuade him to turn these secrets over to Helium in return for Helium's assistance in the work of wreaking his vengeance upon Tul Axtar.
"Phor Tak," I said, "you hold here within your grasp two secrets which in the hands of a kindly and beneficent power would bring eternal peace to Barsoom."
"Heigh-oo!" he cried. "I do not want peace. I want war. War! War!"
"Very well," I agreed, realizing that my suggestion had not been in line with the mad processes of his crazed brain. "Let us have war then, and what country upon Barsoom is better equipped to wage war than Helium? If you want war, form an alliance with Helium."
"I do not need Helium," he cried. "I do not need to form alliances. I shall make war-I shall make war alone. With the invisible Flying Death I can destroy whole navies, whole cities, entire nations. I shall start with Jahar. Tul Axtar shall be the first to feel the weight of my devastating powers. When the fleet of Jahar has tumbled upon the roofs of Jahar and the walls of Jahar have fallen about the ears of Tul Axtar, then shall I destroy Tjanath. Helium shall know me next. Proud and mighty Helium shall tremble and bow at the feet of Phor Tak. I shall be Jeddak of Jeddaks, ruler of a world." As he spoke his voice rose to a piercing shriek and he trembled in the grip of the frenzy that held him.
He must be destroyed, not alone for the sake of Helium, but for the sake of all Barsoom; this mad mind must be removed if I found that it was impossible to direct or cajole it to my own ends. I determined, however, to omit no sacrifice that might tend to bring about a satisfactory conclusion to this strange adventure. I knew that mad minds were sometimes fickle minds and I hoped that in a moment of insane caprice Phor Tak might reveal to me the secret of The Flying Death and the compound of invisibility. This hope was his temporary reprieve from death; its fulfillment would be his pardon, but I knew that I must work warily-that at the slightest suggestion of duplicity, Phor Tak's suspicions would be aroused and that I should then be the one to be destroyed.
I tossed long upon my sleeping silks and furs that night in troubled thought and planning. I felt that I must possess these secrets; yet how? That they existed within his brain alone, I knew, for he had told me that there were no written formulas, or plans or specifications for either of them. Somehow I must wheedle them out of him and the best way to start was to ingratiate myself with him. To this end I must further his plans insofar as I possibly could.
Just before I fell asleep my thoughts reverted to Sanoma Tora and to the urgent mission that had led me to enter upon what had developed into the strangest adventure of my career. I felt a twinge of self-reproach as I suddenly realized that Sanoma Tora had not been uppermost in my mind while I had lain there making plans for the future, but now with recollection of her a plan was suggested whereby I might not only succor her but also advance myself in the good graces of Phor Tak at the same time, and, thus relieved, I fell asleep.
It was late the following morning before I had an opportunity to speak with the old inventor when I immediately broached the subject that was uppermost in my mind. "Phor Tak," I said, "you are handicapped by lack of knowledge of conditions existing in Jahar and the size and location of the fleet. Nur An and I will go to Jahar for you and obtain the information that you must have if your plans are to be successful. In this way, Nur An and I will also be striking a blow at Tul Axtar while we will be in a position to attend to those matters which require our presence in Jahar."
"But how will you get to Jahar?" demanded Phor Tak.
"Could not you let us take a flier?" I asked.
"I have none," replied Phor Tak. "I know nothing about them. I am not interested in them. I could not even build one."
To say that I was both surprised and shocked would be putting it mildly, but if I had previously entertained any doubts that Phor Tak's brain was abnormally developed, it would have vanished with his admission that he knew nothing about fliers, for it seemed to me that there was scarcely a man, woman or child in any of the flying nations of Barsoom but could have constructed some sort of a flier.