Taking her by the hand I moved to the window through which I had entered the apartment, but fortunately I reconnoitered before stepping out into the avenue and it was well for us that I did so, for as I looked to the right along the face of the building, I saw a green Martian warrior emerging from the main entrance. Evidently it had been the rattling of his side arms that we had heard as he moved across the adjoining apartment to the doorway. "Is there another exit from this room?" I asked in a low whisper. "Yes," she replied. "Opposite this window there is a doorway leading into a corridor. It was open when they brought me in, but they closed it." "We shall be better off inside the building than out for a while at least," I said. "Come!" And together we crossed the apartment, groping along the wall for the door which I soon located. With the utmost care I drew it ajar, fearing that its ancient hinges might betray us by their complaining. Beyond the doorway lay a corridor dark as the depths of Omean and into this I drew the girl, closing the door silently behind us. Groping our way to the right away from the apartment occupied by the green warriors, we moved slowly through a black void until presently we saw just ahead a faint light, which investigation revealed as coming through the open doorway of an apartment that faced upon the central courtyard of the edifice. I was about to pass this doorway and seek a hiding place further within the remote interior of the building when my attention was attracted by the squealing of a thoat in the courtyard beyond the apartment we were passing. From earliest boyhood I have had a great deal of experience with the small breed of thoats used as saddle animals by the men of my race and while I was visiting Tars Tarkas of Thark I became quite familiar with the methods employed by the green men in controlling their own huge vicious beasts. For travel over the surface of the ground the thoat compares to other methods of land transportation as the one-man scout flier does to all other ships of the air in aerial navigation. He is as once the swiftest and the most dangerous, so that, faced as I was with a problem of land transportation, it was only natural that the squeal of the thoats should suggest a plan to my mind. "Why do you hesitate?" asked the girl. "We cannot escape in that direction since we cannot cross the courtyard." "On the contrary," I replied, "I believe that in this direction may lie our surest avenue of escape." "But their thoats are penned in the courtyard," she remonstrated, "and green warriors are never far from their thoats." "It is because the thoats are there that I wish to investigate the courtyard," I replied. "The moment they catch our scent," she said, "they will raise a disturbance that will attract the attention of their masters and we shall immediately be discovered and captured."