The passage bulged and became a hall, and here it seemed to him that he saw some blue object before him. He stood, uncertain what it was, and whether to venture towards it. Presently he discovered that it was a patch of light, a reflection of some of the moonlit vapor in the sky falling through a small orifice far, far above in a dome, the height of which he could not measure. In contrast with the yellow flame of his candle, this feeble spot had looked blue as a turquoise. He tried to recollect the plan sketched on the board, and he did remember that this hall was there indicated, with _Ibi lumen_ scrawled beside it. He traversed this hall and entered another passage, or a continuance of the same, beyond. Then he put his hand to his brow, and endeavored to recall the sketch of the mine--and felt that it was gone from him. While lying in prison at Careg Cennen he had recalled it distinctly--he now, indeed, remembered that there was a direction _in sinistram_ or _ad dextram_, he could not now say which, and where the turn was to be made. However, there surely could be no mistake--as he had the way open before him. Hitherto he had felt no fear. Possibly his incarceration in partial darkness had accustomed him to some such places; he pushed on, moreover, animated with hope. And he placed some confidence in his blessed taper from the church of the patron of his family and tribe. But suddenly he sprang back, and only just in time. In front of him, occupying the whole width of the passage, was a hole. How deep it was he had some means of judging by hearing the bound and rebound of a stone dislodged by his foot. "_Cave puteum_;" now he recalled the warning. He crept forward cautiously, and extended his light over the gulf. It illumined the sides but a little way down. Judging by the time a stone took in falling before it plashed into water, it must have been about fifty feet in depth. The well was not large at the mouth. And now Pabo distinctly remembered that the _Thesaurus_ was not far beyond it. It did not occur to him to return. He was so near the goal that reach it he must. He examined attentively the sides. Not a thread of a track existed whereby the abyss might be skirted. There were no pieces of wood about by means of which it could be bridged. The well's mouth was but four feet in diameter. Surely he could leap that! He stepped back two, three strides, and bounded. He reached the ground beyond, but in the spring his light was extinguished. The snuff was glowing, and he blew on it, but it would not flame. "It matters not," said he. "I have my tinder and steel; I can relight it. Now on, on to the gold!"