When I had done Ras Thavas laid a hand upon my shoulder. “I could not have done better myself,” he said. He seemed much elated and I could not but wonder at this unusual demonstration of emotion upon his part, he who so prided himself upon his lack of emotionalism. I had often pondered the purpose which influenced Ras Thavas to devote so much time to my training, but never had I hit upon any more satisfactory explanation than that he had need of assistance in his growing practice. Yet when I consulted the records, that were now open to me, I discovered that his practice was no greater than it had been for many years; and even had it been there was really no reason why he should have trained me in preference to one of his red-Martian assistants, his belief in my loyalty not being sufficient warrant, in my mind, for this preferment when he could, as well as not, have kept me for a bodyguard and trained one of his own kind to aid him in his surgical work. But I was presently to learn that he had an excellent reason for what he was doing—Ras Thavas always had an excellent reason for whatever he did. One night after we had finished our evening meal he sat looking at me intently as he so often did, as though he would read my mind, which, by the way, he was totally unable to do, much to his surprise and chagrin; for unless a Martian is constantly upon the alert any other Martian can read clearly his every thought; but Ras Thavas was unable to read mine. He said that it was due to the fact that I was not a Barsoomian. Yet I could often read the minds of his assistants, when they were off their guard, though never had I read aught of Ras Thavas’ thoughts, nor, I am sure, had any other read them. He kept his brain sealed like one of his own blood jars, nor was he ever for a moment found with his barriers down. He sat looking at me this evening for a long time, nor did it in the least embarrass me, so accustomed was I to his peculiarities. “Perhaps,” he said presently, “one of the reasons that I trust you is due to the fact that I cannot ever, at any time, fathom your mind; so, if you harbor traitorous thoughts concerning me I do not know it, while the others, every one of them, reveal their inmost souls to my searching mind and in each one there is envy, jealousy or hatred of me. Them, I know, I cannot trust. Therefore I must accept the risk and place all my dependence upon you, and my reason tells me that my choice is a wise one—I have told you upon what grounds it based my selection of you as my bodyguard. The same holds true in my selection of you for the thing I have in mind. You cannot harm me without harming yourself and no man will intentionally do that; nor is there any reason why you should feel any deep antagonism towards me.