"What is it you wish me to do?" I asked.

I shall not attempt to quote his exact words; but this, in effect, is what he told me: Multis Par's disappearance from Zor was caused by his capture by men from Sasoom. For some time they had been coming to this planet, reconnoitering, having in mind the eventual conquest of Barsoom.

I asked him for what reason, and he explained that it was simply because they were a warlike race. Their every thought was of war, as it had been for ages until the warlike spirit was as compelling as the urge for self-preservation. They had conquered all other peoples upon Sasoom and sought a new world to conquer.

They had captured him to learn what they could of the armaments and military effectiveness of various Barsoomian nations, and had decided that as Helium was the most powerful, it would be Helium upon which they would descend.

Helium once disposed of the rest of Barsoom would, they assumed, be easy to conquer.

"And where do I come in in this scheme of theirs?" I asked. "I am coming to that," said U Dan. "The Morgors are a thorough-going and efficient people. They neglect no littlest detail which might effect the success or failure of a campaign. They already have excellent maps of Barsoom and considerable data relative to the fleets and armament of the principal nations. They now wish to check this data and obtain full information as to the war technique of the Heliumites. This they expect to get from you. This they will get from you."

I smiled. "Neither they nor you rate the honor and loyalty of a Heliumite very highly."

A sad smile crossed his lips. "I know how you feel," he said. "I felt the same way-until they captured Vaja and her life became the price of my acquiescence. Only to save her did I agree to act as a decoy to aid in your capture. The Morgors are adepts in individual and mass psychology as well as in the art of war."

"These things are Morgors?" I asked, nodding in the direction of some of the repulsive creatures. U Dan nodded. "I can appreciate the position in which you have been placed," I said, "but the Morgors have no such hold on me."

"Wait," said U Dan.

"What do you mean?" I demanded.

"Just wait. They will find a way. They are fiends. No one could have convinced me before Multis Par came to me with his proposition that I could have been forced to betray a man whom I, with all decent men, admire as I have admired you, John Carter. Perhaps I was wrong, but when I learned that Vaja would be tortured and mutilated after Multis Par had had his way with her and even then not be allowed to die but kept for future torture, I weakened and gave in. I do not expect you to forgive, but I hope that you will understand."

"I do understand," I said. "Perhaps, under like circumstances, I should have done the same thing." I could see how terribly the man's conscience tortured him. I could see that he was essentially a man of honor. I could forgive him for the thing that he had done for an innocent creature whom he loved, but could he expect me to betray my country, betray my whole world, to save a woman I had never seen. Still, I was bothered. Frankly, I did not know what I should do when faced with the final decision. "At least," I said, "should I ever be situated as you were, I could appear to comply while secretly working to defeat their ends."

"It was thus that I thought," he said. "It is still the final shred by which I cling to my self-respect. Perhaps, before it is too Late, I may still be able to save both Vaja and yourself."

"Perhaps we can work together to that end and to the salvation of Helium," I said; "though I am really not greatly worried about Helium. I think she can take care of herself."

He shook his head. "Not if a part, even, of what Multis Par has told me is true. They will come in thousands of these ships, invisible to the inhabitants of Barsoom. Perhaps two million of them will invade Helium and overrun her two principal cities before a single inhabitant is aware that a single enemy threatens their security. They will come with lethal weapons of which Barsoomians know nothing and which they cannot, therefore, combat."

"Invisible ships!" I exclaimed. "Why I saw this one plainly after I was captured."

"Yes," he said. "It was not invisible then, but it was invisible when it came in broad daylight under the bows of your patrol ships and landed in one of the most prominent places in all Lesser Helium. It was not invisible when you first saw it; because it had cast off its invisibility, or, rather, the Morgors had cast it off so that they might find it again themselves, for otherwise it would have been as invisible to them as to us."

"Do you know how they achieve this invisibility?" I asked.

"Multis Par has explained it to me," relied U Dan. "Let me see; I am not much of a scientist, but I think that I recall more or less correctly what he told me. It seems that on some of the ocean beaches on Sasoom there is a submicroscopic, magnetic sand composed of prismatic crystals. When the Morgors desire invisibility for a ship, they magnetize the hull; and then from countless tiny apertures in the hull, they coat the whole exterior of the ship with these prismatic crystals. They simply spray them out, and they settle in a cloud upon the hull, causing light rays to bend around the ship. The instant that the hull is demagnetized, these tiny particles, light as air, fall or are blown off; and instantly the ship is visible again."

Here, a Morgor approached and interrupted our conversation. His manner was arrogant and rude. I could not understand his words, as he spoke his own language in the hollow, graveyard tones I had previously noticed. U Dan replied in the same language but in a less lugubrious tone of voice; then he turned to me.

"Your education is to commence at once," he said, with a wry smile.

"What do you mean?" I asked.

"During this voyage you are to learn the language of the Morgors," he explained.

"How long is the voyage going to last?" I asked. "It takes about three months to learn a language well enough to understand and make yourself understood."

"The voyage will take about eighteen days, as we shall have to make a detour of some million miles to avoid the Asteroids. They happen to lie directly in our way."

"I am supposed to learn their Language in eighteen days?" I asked.

"You are not only supposed to, but you will," replied U Dan.

My education commenced. It was inconceivably brutal, but most effective. My instructors worked on me in relays, scarcely giving me time to eat or sleep. U Dan assisted as interpreter, which was immensely helpful to me, as was the fact that I am exceedingly quick in picking up new languages. Sometimes I was so overcome by lack of sleep that my brain lagged and my responses were slow and inaccurate. Upon one such occasion, the Morgor who was instructing me slapped my face. I had put up with everything else; because I was so very anxious to learn their language-a vital necessity if I were ever to hope to cope with them and thwart their fantastic plan of conquest. But I could not put up with that. I hit the fellow a single blow that sent him entirely across the cabin, but I almost broke my hand against his unpadded, bony jaw.

He did not get up. He lay where he had fallen. Several of his fellows came for me with drawn swords. The situation looked bad, as I was unarmed. U Dan Was appalled. Fortunately for me, the officer in command of the ship had been attracted by the commotion and appeared at the scene of action in time to call his men off. He demanded an explanation.

I had now mastered sufficient words of their language so that I could understand almost everything that was said to me and make myself understood by them, after a fashion. I told the fellow that I had been starved and deprived of sleep and had not complained, but that no man could strike me without suffering the consequences.