For a moment Tristan's heart stood still, then, with all the caution which the darkness, the danger of secret pitfalls and the risk of discovery suggested, he crept toward the crevice until the glow gradually increased. From the bowels of the earth, as it were, voices were now audible; they seemed to issue from the depths of a cavern directly below where Tristan stood. Groping his way carefully along the wall of rock, he at last reached the spot whence the light issued and presently started at finding himself before an aperture just wide enough to admit the body of a single man. A sort of perpendicular ladder was formed in the wall of narrow juttings of stone, and below these was the rock chamber from which the voices proceeded. It was some time ere the confusion of his ideas and the darkness allowed Tristan to form any notion of the character of the locality, when it suddenly dawned upon him that he had strayed into a place regarding which he had heard and wondered much: the Catacombs of St. Calixtus. This revelation was by no means reassuring, although the presence of others held out hope that he would discover an exit from this shadowy labyrinth. For a moment Tristan remained as one transfixed, as he gazed from his lofty pinnacle into the shadowy vault below. He saw a stone table, lighted with a single taper, in the centre of which lay an unsheathed dagger, and an object the exact character of which he could not determine in the half gloom, also a brazen bowl. About a dozen men in cloaks with black vizors stood around, and one, taller than the rest, the gleam of whose eyes shone through the slits of his mask, appeared to be concluding an address to his companions. The words were indistinguishable to Tristan but, when the speaker had concluded, a dark murmur arose which subsided anon. Then those present crowded around the stone table. The taper was momentarily obscured by the intervening throng, and Tristan could not see the ceremony, though he could hear the muttered formula of an oath they seemed to be taking. What he did see caused the chill of death to run through his veins. The group again receding, the man bared his left arm, raised the dagger on high and let it descend. Tristan saw the blood weltering slowly from the self-inflicted wound, trickling drop by drop into the brazen bowl, which another muffled figure was holding. Then each one present repeated the ceremony, he who was presenting the bowl being the last to mingle his blood with that of the rest. Then another stepped forth and, raising the bloody knife on high, stabbed the object that lay upon the table. Some mysterious signs passed between them, meaningless words that struck Tristan's ear with the vague memory of a dimly remembered dream. Then he who seemed to be the speaker raised the object on high and, walking to a niche, concealed in the shadows, placed it in, what seemed to Tristan, a fissure in the rock.