I moved a short distance out of their course and then swung my periscope toward them again. To my astonishment I discovered that they, too, had altered their course and were following me.

Now I rose swiftly and took a new direction, but when I looked again the craft was bearing down upon me and not only that, but she was training a gun on me.

What had happened? It was evident that something had gone wrong and that I was no longer clothed in total invisibility, but whatever it was, it was too late now to rectify it even if I could. I had but a single recourse and I prayed to my first ancestor that it might not now be too late to put it into execution. Should they fire upon me, I was lost.

I brought the Jhama to a full stop and sprang quickly aft to where the rear rifle was mounted on a platform just within the after turret.

In that instant I had occasion to rejoice in the foresight that had prompted me to rearrange the projectiles properly against the necessity for instant use in such an emergency as this. Selecting one, I jammed it into the chamber and closed the breech block. The turret, crudely and hastily constructed though it had been, responded to my touch and an instant later my sight covered the approaching patrol vessel, and through the tiny opening provided for the sight I witnessed the effect of my first shot with Phor Taks disintegrating ray rifle.

I had used a metal disintegrating projectile and the result was appalling.

I loved a ship and it tore my heart to see that staunch craft fall apart in midair as its metal parts disappeared before the disintegrating ray.

But that was not all, as wood and leather and fabric sank with increasing swiftness toward the ground, brave warriors hurtled to their doom. It was horrifying.

I am a true son of Barsoom; I joy in battle; armed conflict is my birthright, and war the goal of my ambition, but this was not war; it was murder.

I took no joy in my victory as I had when I laid Yo Seno low in mortal combat, and now, more than ever, was I determined that this frightful instrument of destruction must in some way be forever banned upon Barsoom. War with such a weapon completely hidden by the compound of invisibility would be too horrible to contemplate. Navies, cities, whole nations could be wiped out by a single battle thus equipped. The mad dream of Phor Tak might easily come true and a maniac yet rule all Barsoom.

But meditation and philosophizing were not for me at this time. I had work to do and though it necessitated wiping out all Tjanath, I purposed doing it.

Again the sirens and the gongs raised their wild alarm; again patrol boats gathered. I felt that I must depart until after nightfall, for I had no stomach to again be forced to turn that deadly rifle upon my fellow men while any alternative existed.

As I started to turn back the controls my eyes chanced to fall upon one of the stern ports and, to my surprise, I saw that the shutter was raised. How this occurred I do not know; it has always remained a mystery, but at least it explained how it had been possible for the patrol boat to follow me. That round port hole moving through the air must have filled them with wonder, but at the same time it was a clue to follow and though they did not understand it, they, like the brave warriors that they were, followed it in the line of their duty.

I quickly closed it, and, after examining the others and finding them all closed, I was now confident that, with the exception of the small eye of my periscope, I was entirely surrounded by invisibility and hence under no immediate necessity for leaving the vicinity of the palace, as I could easily maneuver the ship to keep out of the way of the patrol boats that were now again congregating near the royal hangar.

I think they were pretty much upset by what had happened and evidently there was no unanimity of opinion as to what should be done. The patrol ships hovered about, evidently waiting orders, and it was not until almost dark that they set out in a systematic search of the air above the city; nor had they been long at this before I understood their orders as well as though I had read them myself. The lower ships moved at an altitude of not over fifty feet above the higher buildings; two hundred feet above these moved the second line. The ships at each level cruised in a series of concentric circles and in opposite directions, thereby combing the air above the city so closely that no enemy ship could possibly approach. The air below was watched by a thousand eyes; at every point of vantage sentries were on watch and upon the roof of every public building guns appeared as if by magic.

I began to be quite apprehensive that even the small eye of my periscope might not go undetected and so I dropped my ship into a little opening among some lofty trees that grew within the palace garden, and here I waited some twenty feet above the ground, my periscope completely screened from view, unseen and, in consequence, myself unseeing, until the swift night of Barsoom descended upon Tjanath; then I rose slowly from my leafy retreat.

Above the trees I paused to have a look about me through the periscope. Far above me were the twinkling lights of the circling patrol boats and from a thousand windows of the palace shone other lights. Before me rose the dark outlines of the East Tower silhouetted against the starry sky.

Rising slowly I circled the tower until I had brought the Jhama opposite Tavia's window.

My ship carried no lights, of course, and I had not switched on any of the lights within her cabin, so that I felt that I might with impunity raise one of the upper hatches, and this I did. The Jhama lay with her upper deck a foot or two beneath the sill of Tavia's window. Before venturing from below I replaced my cloak of invisibility about me.

There was no light in Tavia's room. I placed my ear close against the iron bars and listened. I could hear no sound. My heart sank within me. Could it be that they had removed her to some other part of the palace? Could it be that Haj Alt had come and taken her away? I shuddered at the mere suggestion and cursed the luck that had permitted him to escape my blade.

With all those eyes and ears straining through the darkness I feared to make the slightest sound, though I felt that there was little likelihood that the open hatch would be noticed in the surrounding darkness; yet I must ascertain whether or not Tavia was within that room. I leaned close against the bars and whispered her name. There was no response.

"Tavia!" I whispered, this time much louder, and it seemed to me that my voice went booming to high heaven in tones that the dead might hear.

This time I heard a response from the interior of the room. It sounded like a gasp and then I heard someone moving-approaching the window. It was so dark in the interior that I could see nothing, but presently I heard a voice close to me.

"Hadron! Where are you?"

She had recognized my voice. For some reason I thrilled to the thought of it. "Here at the window, Tavia," I said.

She came very close. "Where?" she asked. "I cannot see you."

I had forgotten my robe of invisibility. "Never mind," I said. "You cannot see me, but I will explain that later. Is Phao with you?"

"Yes."

"And no one else?"

"No."

"I am going to take you with me, Tavia-you and Phao. Stand aside well out of line of the window so that you will not be hurt while I remove the bars. Then be ready to board my ship immediately."

"Your ship!" she said. "Where is it?"

"Never mind now. There is a ship here. Do just as I tell you. Do you trust me?"

"With my life, Hadron, forever," she whispered.

Something within me sang. It was more than a mere thrill; I cannot explain it; nor did I understand it, but now there were other things to think of.