Tarzan smiled and slipped over the edge of the embrasure. In one hand he carried the rod that he had retained as a weapon, with the other he clung to the window ledge. Below him for eighteen huals dangled the slender ladder of iron hooks, and below this, four hundred huals of pitchy darkness hid the stone flagging of the inner courtyard. Perhaps it roofed the great central throne room of the king, as was true in the royal dome of Adendrohahkis; perhaps it was but an open court. The truth was immaterial if the frail support slipped from the shallow hole in the ledge above, or if one of the hooks straightened under the weight of the ape-man. Now he grasped the upper section of his ladder with the hand that held his improvised weapon, removed the hand from the ledge and grasped the rod again, still lower down. In this way he lowered his body a few inches at a time. He moved very slowly for two reasons, the more important of which was that he feared that any sudden strains upon his series of hooks might straighten one of them and precipitate him into the abyss below; the other was the necessity for silence. It was very dark even this close to the summit of the dome, but that was rather an advantage than otherwise, for it hid his presence from any chance observer who might glance through one of the embrasures in the opposite wall of the shaft. As he descended he felt in both directions for an embrasure, but he was almost at the end of his ladder before he felt himself swing slightly into one. When he had lowered himself still farther and could look into the opening he saw that it was dark, an indication that it did not lead into an inhabited chamber, a fact for which he was thankful. He hoped, too, that the inner end of the embrasure was not barred, nor the door beyond bolted upon the outside. He whistled once, very low, for Komodoflorensal, and an instant later he felt the movement of the iron ladder that told him his companion had commenced the descent. The embrasure in which he stood was higher than the one they had just quitted, permitting him to stand erect. There he waited for the Trohanadalmakusian who was soon standing upon the ledge beside him. "Whew!" exclaimed the prince, in a whisper. "I should hate to have had to do that in the daytime when I could have seen all the way to the bottom. What next? We have come farther already than ever I dreamed would be possible. Now I am commencing to believe that escape may lie within the realm of possibilities." "We haven't started yet," Tarzan assured him; "but we are going to now. Come!"