As we approached the first courtyard, I suddenly broke away from my guard and ran ahead with all my earthly speed. The warrior shouted for me to halt, and broke into a run. As I reached the entrance to the courtyard I pretended to dodge around the corner, which would of course have hidden me from him.

I must confess that in that short sprint my heart had been in my mouth, for of course I could not know whether or not I should become invisible.

However, the moment that I left the lighted corridor I absolutely disappeared; I could not see any part of my body—it was the strangest sensation that I have ever experienced.

I had made my plans, and now I ran to the far end of the courtyard and leaped lightly to the roof of the city.

I could hear the warrior guard rushing about calling to me; my disappearance must certainly have mystified him, for having no idea that I could become invisible, there was really no way in which he could account for it except on the theory that I had run into the entrance to another street. However, he was probably confident that I did not have time to do this.

Well, I did not bother much about him or what he was thinking; instead I took off across the roof in search of the courtyard where Ptor Fak was awaiting me and where I expected to meet Rojas at midnight; and it was pretty close to what we call midnight then, the Barsoomian midnight occurring twenty-five xats after the eighth zode.

A Martian day is divided into ten zodes, there being four tals to a xat, or two hundred to a zode. The dials of their clocks are marked with four concentric circles; between the inner circle and the next outer one the Zodes are marked from one to ten; in the next circle, the xats are marked from one to fifty between each two zodes; and in the outer circle two hundred tals are marked between the radii which pass through the zode numbers and extend to the outer periphery of the dial. Their clock has three different colored and different length hands, one indicating the zode, the second one the xat, and the longest one the tal.

(Editor's note: I have before me the diagram of the dial of a Martian clock drawn for me by John Carter many years ago.) I had no difficulty in finding the courtyard in which I had been confined; and when I reached it I whistled, and Ptor Fak answered. I dropped down into it and whistled again, and when Ptor Fak answered I groped around until I bumped into him.

"How well you look," he said, and we both laughed. "It took you much longer to dispose of Motus than I had anticipated," he continued.