"Where are you from, Dotar Sojat?" asked, Kandus.

"From Virginia," I said.

"That is a city of which I have never heard. In what country is it?"

"It is in the United States of America," I replied, "but you never heard of that either."

"No," he admitted; "that must be a far country."

"It is a far country," I assured him, "some forty-three million miles from here."

"You can talk as tall as you jump," he said. "I don't mind your joking with me," he added, "but I wouldn't get funny with Pnoxus, nor with Ptantus, the jeddak, if I were you; neither one of them has a sense of humor."

"But I was not joking," I insisted. "You have seen Jasoom in the heavens at night?"

"Of course," he replied.

"Well, that is the world I come from; it is called Earth there, and Barsoom is known as Mars."

"You look and talk like an honorable man," said Kandus; "and, while I don't understand, I am inclined to believe; however, you'd better pick out some place on Barsoom as your home when anyone else in Invak questions you; and you may soon be questioned-here we are at the gates of the city now."

Invak! The city in the Forest of Lost Men. At first only a gate was visible, so thickly set were the trees that hid the city wall-the trees and the vines that covered the wall.

I heard a voice challenge as we approached the gate, and I heard Pnoxus's voice reply, "It is Pnoxus, the prince, with twenty warriors and a prisoner."

"Let one advance and give the countersign," said the voice.

I was astonished that the guard at the gate couldn't recognize the jeddak's son, nor any of the twenty warriors with him. I suppose that one of the voices advanced and whispered the countersign, for presently a voice said, "Enter, Pnoxus, with your twenty warriors and your prisoner."

Immediately the gates swung open, and beyond I saw a lighted corridor and people moving about within it; then my rope tightened and I moved forward toward the gate; and ahead of me, one by one, armed men suddenly appeared just beyond the threshold of the gateway; one after another they appeared as though materialized from thin air and continued on along the lighted corridor. I approached the gate apparently alone, but as I stepped across the threshold there was a warrior at my side where the voice of Kandus had walked.

I looked at the warrior, and my evident amazement must have been written large upon my face, for the warrior grinned. I glanced behind me and saw warrior after warrior materialize into a flesh-and-blood man the moment that he crossed the threshold. I had walked through the forest accompanied only by voices, but now ten warriors walked ahead of me and nine behind and one at my side.

"Are you Kandus?" I asked this one.

"Certainly," he said.

"How do you do it?" I exclaimed.

"It is very simple, but it is the secret of the Invaks," he replied. "I may tell you, however, that we are invisible in daylight, or rather when we are not illuminated by these special lamps which light our city. If you will notice the construction of the city as we proceed, you will see that we take full advantage of our only opportunity for visibility."

"Why should you care whether other people can see you or not?" I asked. "Is it not sufficient that you can see them and yourselves?"

"Unfortunately, there is the hitch," he said. "We can see you, but we can't see each other any more than you can see us."

So that accounted for the grumbling and cursing I had heard upon the march through the forest-the warriors had been getting in each other's way because they couldn't see one another any more than I could see them.

"You have certainly achieved invisibility," I said, "or are you hatched invisible from invisible eggs?"

"No," he replied, "we are quite normal people; but we have learned to make ourselves invisible."

Just then I saw an open courtyard ahead of us, and as the warriors passed out of the lighted corridor into it they disappeared. When Kandus and I stepped out, I was walking alone again. It was most uncanny.

The city was spotted with these courtyards which gave ventilation to the city which was, otherwise, entirely roofed and artificially lighted by the amazing lights which gave complete visibility to its inhabitants. In every courtyard grew spreading trees, and upon the city's roof vines had been trained to grow; so that, built as it was in the center of the Forest of Lost Men, it was almost as invisible from either the ground or the air as were its people themselves.

Finally we halted in a large courtyard in which were many trees wherein iron rings were set with chains attached to them, and here invisible hands snapped around one of my ankles a shackle that was fastened to the end of one of these chains.

Presently a voice whispered in my ear, "I will try to help you, for I have rather taken a liking to you-you've got to admire a man who can jump thirty feet into the air; and you've got to be interested in a man who says he comes from another world forty-three million miles from Barsoom."

It was Kandus. I felt that I was fortunate in having even the suggestion of a friend here, but I wondered what good it would do me. After all, Kandus was not the jeddak; and my fate would probably rest in the hands of Ptantus.

I could hear voices crossing and recrossing the courtyard. I could see people come down the corridors or streets and then fade into nothingness as they stepped out into the courtyard. I could see the backs of men and women appear quite as suddenly in the entrances to the streets as they left the courtyard. On several occasions voices stopped beside my tree and discussed me. They commented upon my light skin and gray eyes. One voice mentioned the great leap into the air that one of my captors had recounted to its owner.

Once a delicate perfume stopped near me, and a sweet voice said, "The poor man, and he is so handsome!"

"Don't be a fool, Rojas," growled a masculine voice. "He is an enemy, and anyway he's not very good-looking."

"I think he is very good-looking," insisted the sweet voice, "and how do you know he's an enemy?"

"I was not an enemy when I brought my ship down beside the forest," I said, "but the treatment I have received is fast making one of me."

"There, you see," said the sweet voice; "he was not an enemy. What is your name, poor man?"

"My name is Dotar Sojat, but I am not a 'poor man,'" I replied with a laugh.

"That may be what you think," said the masculine voice. "Come on, Rojas, before you make any bigger fool of yourself."

"If you'll give me a sword and come out of your cowardly invisibility, I'll make a fool of you, calot," I said.

An invisible, but very material, toe kicked me in the groin. "Keep your place, slave!" growled the voice.

I lunged forward and, by chance, got my hands on the fellow; and then I held him by his harness for just long enough to feel for his face, and when I had located it I handed him a right upper-cut that must have knocked him half way across the courtyard.

"That," I said, "will teach you not to kick a man who can't see you."

"Did Motus kick you?" cried the sweet voice, only it wasn't so sweet now; it was an angry voice, a shocked voice. "You looked as though you were hitting him-I hope you did."

"I did," I said, "and you had better see if there is a doctor in the house."

"Where are you, Motus?" cried the girl.

There was no response; Motus must have gone out like a light. Pretty soon I heard some lurid profanity, and a man's voice saying, "Who are you, lying around here in the courtyard?" Some voice had evidently stumbled over Motus.

"That must be Motus," I said in the general direction from which the girl's voice had last come. "You'd better have him carried in."