Apparently this familiar sound had penetrated in some degree to his inner consciousness. An expression of vague uneasiness, of troubled irresolution, clouded his eyes, but this semi-intellection and its transient phasis subsided to his original apathy as, with a sigh of helpless impersonality, he began to collect, with a silly, childish selection, as if to balance, by the size of the individual coals, the proportion of the discharged gold, handfuls of these dusky diamonds and substitute the sordid heaps in the bag. This weird absurdity concluded, Raikes, repossessing himself of the candle, turned wearily and retraced the path of his ghostly journey. In a little while his shuffling footfalls had concluded with the doorway at the top of the cellar stairs, the latch was heard to click into place, and all was still. "Now," whispered Gratz with concentrated emphasis, "not a word--not a sound from this moment. We have seen the accessory, now for the principal." In reply Robert pressed his hand upon the arm of the detective to indicate that his instructions were understood and would be obeyed, and in a silence through which he felt that his heart-throbs must certainly be audible, the watchers awaited developments. The obscurity and silence which prevailed, and the vault-like chill and dampness, harmonized so fully with the unnatural spectacle which he had just witnessed, and the grim expectation of something untoward still to come, that Robert was prepared to reconsider his views of the earlier portion of the evening as to his fitness for secret investigation and criminal analysis. He no longer felt the exultation of this association with relentless and cunning pursuit, and began to wonder how any normal human being could adopt a profession which embraced all these cheerless handicaps when there were so many occupations into which a little sunlight and geniality penetrated now and then. He had about decided that such industry was the manifestation of a disease, and that his silent companion was a desperate incurable, when his diagnosis was suddenly interrupted. The detective pressed the shoulders of his companion, communicating a slight impulse toward the opposite end of the cellar, and Robert, in obedience to its intimation, turned and beheld an approaching light. It had the unreal appearance of a detached eye of some malignant Cyclops, glancing in a ghastly, bodiless way, from object to object, and concentrating itself at last in a definite course along the floor. To witness the approach of this stealthy, gleam, without visible means of support or guidance, caused the young man's flesh to creep and his heart to throb almost to the point of suffocation. If it requires experience to become a successful narrator, Robert was certainly in a way to accumulate a budget of startling data.