Just outside the great arch that had once been the doorway he paused, and stood for a moment with ears strained for any sound from within; but the place was wrapped in silence as in a shroud, and, reassured, he crossed the threshold. There was danger in his enterprise other than that from savages. At any moment a block of stone might come crashing from the walls, and, were he beneath such, his career would be ended on the spot. Knowing this, he made his examination as brief as possible, keeping well back from the walls. The building appeared to have been used as a temple at one time, for in the centre stood a stone altar. Time, the destroyer, had not quite obliterated the rude hieroglyphics with which the side of the sacrificial slab had been covered, but Wilson could not gain from them the information he so much desired. To him they were mere meaningless scratches. Mervyn, perhaps, could have read in them the life-history of the builders of the place; but the engineer’s education did not include the sign languages of defunct races. Suddenly, clear as ever through the silence, came the bell-note. The sound recalled to Wilson the object of his search, the mysterious bell-ringer. Not a little curious as to the identity of the being, whoever it was, he thoroughly examined the interior of the temple--but in vain. The place was entirely deserted. Not a hole was there large enough to conceal a dog, yet the engineer was certain the sound came from the building. Was there a vault beneath the temple? It seemed probable, but how came it that the sound was so distinct if the ringer were underground? The thing puzzled him. Determined to solve the mystery, he examined the moss-grown flags of the floor, but with no better result. Outside the building, when he essayed to search there, failure still attended his efforts. The time flew by, and, though at intervals the musical peal still fell upon his ears, he was no nearer the discovery of the mysterious being; bell and ringer seemed invisible. Probably he would never have hit upon the true solution of the mystery but for an accident. As he moved amidst the fallen blocks which strewed the ground at the base of the walls, he stumbled and fell, whereupon, from the shelter of a stone close by, scuttled an enormous beetle. The creature was almost a foot in length, and its branched antennae, held over its back as it ran, beat furiously upon its metallic body-covering, thus producing the clanging sound which had puzzled Wilson for so long. “Well, I’m hanged!” was the engineer’s graceful exclamation as he rose; “to think that it’s only a beetle, after all! But now ‘to get a move on,’ as Silas would say,” and with that he turned his back upon the mysterious temple and resumed his way.