The officer looked toward the city.

"The watch has seen him," he said; "we may remain, for we may be needed."

I looked toward the city and saw several hundred warriors issuing from the nearest gate. They moved leisurely, as though there were no need for haste-nor was there, as I was presently to learn.

Then I turned my eyes once more toward the flier. She was moving rapidly toward the city, and when she had come close enough I was surprised to see that her propellers were idle.

Straight for that grim shaft she bore. At the last minute I saw the great blades move to reverse her, yet on she came as though drawn by some mighty, irresistible power.

Intense excitement prevailed upon her deck, where men were running hither and thither, manning the guns and preparing to launch the small, one-man fliers, a fleet of which is part of the equipment of every Martian war vessel. Closer and closer to the black shaft the ship sped. In another instant she must strike, and then I saw the familiar signal flown that sends the lesser boats in a great flock from the deck of the mother ship.

Instantly a hundred tiny fliers rose from her deck, like a swarm of huge dragon flies; but scarcely were they clear of the battleship than the nose of each turned toward the shaft, and they, too, rushed on at frightful speed toward the same now seemingly inevitable end that menaced the larger vessel.

A moment later the collision came. Men were hurled in every direction from the ship's deck, while she, bent and crumpled, took the last, long plunge to the scrap-heap at the shaft's base.

With her fell a shower of her own tiny fliers, for each of them had come in violent collision with the solid shaft.

I noticed that the wrecked fliers scraped down the shaft's side, and that their fall was not as rapid as might have been expected; and then suddenly the secret of the shaft burst upon me, and with it an explanation of the cause that prevented a flier that passed too far across the ice-barrier ever returning.

The shaft was a mighty magnet, and when once a vessel came within the radius of its powerful attraction for the aluminum steel that enters so largely into the construction of all Barsoomian craft, no power on earth could prevent such an end as we had just witnessed.

I afterward learned that the shaft rests directly over the magnetic pole of Mars, but whether this adds in any way to its incalculable power of attraction I do not know. I am a fighting man, not a scientist.

Here, at last, was an explanation of the long absence of Tardos Mors and Mors Kajak. These valiant and intrepid warriors had dared the mysteries and dangers of the frozen north to search for Carthoris, whose long absence had bowed in grief the head of his beautiful mother, Dejah Thoris, Princess of Helium.

The moment that the last of the fliers came to rest at the base of the shaft the black-bearded, yellow warriors swarmed over the mass of wreckage upon which they lay, making prisoners of those who were uninjured and occasionally despatching with a sword-thrust one of the wounded who seemed prone to resent their taunts and insults.

A few of the uninjured red men battled bravely against their cruel foes, but for the most part they seemed too overwhelmed by the horror of the catastrophe that had befallen them to do more than submit supinely to the golden chains with which they were manacled.

When the last of the prisoners had been confined, the party returned to the city, at the gate of which we met a pack of fierce, gold-collared apts, each of which marched between two warriors, who held them with strong chains of the same metal as their collars.

Just beyond the gate the attendants loosened the whole terrible herd, and as they bounded off toward the grim, black shaft I did not need to ask to know their mission. Had there not been those within the cruel city of Kadabra who needed succor far worse than the poor unfortunate dead and dying out there in the cold upon the bent and broken carcasses of a thousand fliers I could not have restrained my desire to hasten back and do battle with those horrid creatures that had been despatched to rend and devour them.

As it was I could but follow the yellow warriors, with bowed head, and give thanks for the chance that had given Thuvan Dihn and me such easy ingress to the capital of Salensus Oll.

Once within the gates, we had no difficulty in eluding our friends of the morning, and presently found ourselves in a Martian hostelry.

The public houses of Barsoom, I have found, vary but little. There is no privacy for other than married couples.

Men without their wives are escorted to a large chamber, the floor of which is usually of white marble or heavy glass, kept scrupulously clean. Here are many small, raised platforms for the guest's sleeping silks and furs, and if he have none of his own clean, fresh ones are furnished at a nominal charge.

Once a man's belongings have been deposited upon one of these platforms he is a guest of the house, and that platform his own until he leaves. No one will disturb or molest his belongings, as there are no thieves upon Mars.

As assassination is the one thing to be feared, the proprietors of the hostelries furnish armed guards, who pace back and forth through the sleeping-rooms day and night. The number of guards and gorgeousness of their trappings quite usually denote the status of the hotel.

No meals are served in these houses, but generally a public eating place adjoins them. Baths are connected with the sleeping chambers, and each guest is required to bathe daily or depart from the hotel.

Usually on a second or third floor there is a large sleeping-room for single women guests, but its appointments do not vary materially from the chamber occupied by men. The guards who watch the women remain in the corridor outside the sleeping chamber, while female slaves pace back and forth among the sleepers within, ready to notify the warriors should their presence be required.

I was surprised to note that all the guards with the hotel at which we stopped were red men, and on inquiring of one of them I learned that they were slaves purchased by the proprietors of the hotels from the government. The man whose post was past my sleeping platform had been commander of the navy of a great Martian nation; but fate had carried his flagship across the ice-barrier within the radius of power of the magnetic shaft, and now for many tedious years he had been a slave of the yellow men.

He told me that princes, jeds, and even jeddaks of the outer world, were among the menials who served the yellow race; but when I asked him if he had heard of the fate of Mors Kajak or Tardos Mors he shook his head, saying that he never had heard of their being prisoners here, though he was very familiar with the reputations and fame they bore in the outer world.

Neither had he heard any rumor of the coming of the Father of Therns and the black dator of the First Born, but he hastened to explain that he knew little of what took place within the palace. I could see that he wondered not a little that a yellow man should be so inquisitive about certain red prisoners from beyond the ice-barrier, and that I should be so ignorant of customs and conditions among my own race.

In fact, I had forgotten my disguise upon discovering a red man pacing before my sleeping platform; but his growing expression of surprise warned me in time, for I had no mind to reveal my identity to any unless some good could come of it, and I did not see how this poor fellow could serve me yet, though I had it in my mind that later I might be the means of serving him and all the other thousands of prisoners who do the bidding of their stern masters in Kadabra.