At night I slept, secure in the knowledge that my directional compass would hold a true course for Horz and always at the altitude for which I had set it-a thousand feet, not above sea level but above the terrain over which the ship was passing. These amazing little instruments may be set for any point upon Barsoom and at any altitude. If one is set for a thousand feet, as mine was upon this occasion, it will not permit the ship to come closer than a thousand feet to any object, thus eliminating even the danger of collision; and when the ship reaches its objective the compass will stop it a thousand feet above. The pilot whose ship is equipped with one of these directional compasses does not even have to remain awake; thus I could travel day and night without danger.

It was about noon of the third day that I sighted the towers of ancient Horz.

The oldest part of the city lies upon the edge of a vast plateau; the newer portions, and they are countless thousands of years old, are terraced downward into a great gulf, marking the hopeless pursuit of the receding sea upon the shores of which this rich and powerful city once stood. The last poor, mean structures of a dying race have either disappeared or are only mouldering ruins now; but the splendid structures of her prime remain at the edge of the plateau, mute but eloquent reminders of her vanished grandeur-enduring monuments to the white-skinned, fair-haired race which has vanished forever.

I am always interested in these deserted cities of ancient Mars. Little is known of their inhabitants, other than what can be gathered from the stories told by the carvings which ornament the exteriors of many of their public buildings and the few remaining murals which have withstood the ravages of time and the vandalism of the green hordes which have overrun many of them. The extremely low humidity has helped to preserve them, but more than all else was the permanency of their construction. These magnificent edifices were built not for years but for eternities. The secrets of their mortars, their cements, and their pigments have been lost for ages; and for countless ages more, long after the last life has disappeared from the face of Barsoom, their works will remain, hurtling through space forever upon a dead, cold planet with no eye to see, with no mind to appreciate. It is a sad thing to contemplate.

At last I was over Horz. I had for long promised myself that some day I should come here, for Horz is, perhaps, the oldest and the greatest of the dead cities of Barsoom. Water built it, the lack of water spelled its doom. I often wonder if the people of Earth, who have water in such abundance, really appreciate it.

I wonder if the inhabitants of New York City realize what it would mean to them if some enemy, establishing an air base within cruising radius of the first city of the New World, should successfully bomb and destroy Croton Dam and the Catskill water system. The railroads and the highways would be jammed with refugees, millions would die, and for years, perhaps forever, New York City would cease to be.

As I floated lazily above the deserted city I saw figures moving in a plaza below me. So Horz was not entirely deserted! My curiosity piqued, I dropped a little lower; and what I saw dashed thoughts of solitude from my mind-a lone red man beset by half a dozen fierce green warriors.

I had not sought adventure, but here it was; for no man worthy of his metal would abandon one of his own kind in such a dire extremity. I saw a spot where I might land in a nearby plaza; and, praying that the green men would be too engrossed with their engagement to note my approach, I dove quickly and silently toward a landing.

Fortunately I landed unobserved, screened by a mighty tower which rose beside the plaza I had selected. I had seen that they were fighting with long-swords, and so I drew mine as I ran in the direction of the unequal struggle. That the red man lived even a few moments against such odds bespoke the excellence of his swordsmanship, and I hoped that he would hold out until I reached him; for then he would have the best sword arm in all Barsoom to aid him and the sword that had tasted the blood of a thousand enemies the length and breadth of a world.

I found my way from the plaza in which I had landed, but only to be confronted by a twenty-foot wall in which I could perceive no opening. Doubtless there was one, I knew; but in the time that I might waste in finding it my man might easily be killed.

The clash of swords, the imprecations, and the grunts of fighting men came to me distinctly from the opposite side of the wall which barred my way. I could even hear the heavy breathing of the fighters. I heard the green men demand the surrender of their quarry and his taunting reply. I liked what he said and the way he said it in the face of death.

My knowledge of the ways of the green men assured me that they would try to capture him for purposes of torture rather than kill him outright, but if I were to save him from either fate I must act quickly.

There was only one way to reach him without loss of time, and that way was open to me because of the lesser gravitation of Mars and my great Earthly strength and agility. I would simply jump to the top of the wall, take a quick survey of the lay of the land beyond, and then drop down, long-sword in hand, and take my place at the side of the red man.

When I exert myself, I can jump to incredible heights. Twenty feet is nothing, but this time I miscalculated. I was several yards from the wall when I took a short run and leaped into the air. Instead of alighting on the top of the wall, as I had planned, I soared completely over it, clearing it by a good ten feet.

Below me were the fighters. Apparently I was going to land right in their midst.

So engrossed were they in their sword play that they did not notice me; and that was well for me; as one of the green men could easily have impaled me on his sword as I dropped upon them.

My man was being hard pressed. It was evident that the green men had given up the notion of capturing him, and were trying to finish him off. One of them had him at a disadvantage and was about to plunge a long-sword through him when I alighted. By rare good luck I alighted squarely upon the back of the man who was about to kill the red man, and I alighted with the point of my sword protruding straight below me. It caught him in the left shoulder and passed downward through his heart, and even before he collapsed I had planted both feet upon his shoulders; and, straightening up, withdrawn my blade from his carcass.

For a moment my amazing advent threw them all off their guard, and in that moment I leaped to the side of the red man and faced his remaining foes, the red blood of a green warrior dripping from my point.

The red man threw a quick glance at me; and then the remaining green men were upon us, and there was no time for words. A fellow swung at me and missed. Gad! what a blow he swung! Had it connected I should have been as headless as a rykor. It was unfortunate for the green man that it did not, for mine did. I cut horizontally with all my Earthly strength, which is great on Earth and infinitely greater on Mars. My long-sword, its edge as keen as a razor and its steel such as only Barsoom produces, passed entirely through the body of my antagonist, cutting him in two.

"Well done!" exclaimed the red man, and again he cast a quick glance at me.

From the corner of my eye I caught an occasional glimpse of my unknown comrade, and I saw some marvelous swordsmanship. I was proud to fight at the side of such a man. By now we had reduced the number of our antagonists to three. They fell back a few steps, dropping their points, just for a breathing spell. I neither needed nor desired a breathing spell; but, glancing at my companion, I saw that he was pretty well exhausted; so I dropped my point too and waited.