"The thief?" asked Robert.

"No, the accessory," was the reply; "but do not ask any further questions; you will be treated to the surprise of your life in a little while, unless I am much mistaken."

Scarcely had the detective uttered these words when the faint click of a door-latch was borne to their ears from the direction of the stairway they had just descended.

The next moment a dim ray of light flickered into the darkness, and a figure vaguely shadowed its grotesque disproportion on the walls just behind as it crept, with cautious lightness, step by step down the stairs.

At last it reached the floor and moved in the direction of the bin.

The light, which was furnished by a candle, was raised in the air at about the height of a man's face, and directly behind it a man's face appeared.

"Great heavens!" whispered Robert as the strange figure advanced, "it is uncle!"

"Steady, now!" whispered the detective; "not a word or you will ruin everything."

Revealed by the weird light, the miserable countenance of the miser had never looked so contemptible.

The sputtering flame seemed to have the power to betray all the miserly emotions and mean parsimonies usually concealed behind its starved pallor.

The lips had fallen inanely apart with an absurd look of silly wonder.

The eyes were wide open and stared directly ahead with the most unnatural expression or lack of it that Robert had ever beheld in the visage of mortal man.

Even the detective, accustomed as he was to all sorts of uncommon spectacles, could not repress a slight disposition to shudder.

One bony hand grasped the candlestick, and the other held some sort of round object, to which Robert directed his attention.

By the sudden motion he made the detective knew that the young man had discovered what this object was, and pressed his arm warningly.

_It was one of the canvas bags from the recess in the wall._

Just before the opening of the bin his uncle paused, like a speculative phantom, as if to consider its next doleful move.

His entire countenance, upon nearer view, like the canvas which the painter has roughly outlined, was suggestive of anything, according to the fancy of the beholder.

Upon this spiritless blank Robert depicted, with a morbid genius and the stimulation of his unnatural surroundings, all that was reminiscent of his uncle's littleness.

But this uneasy transit from the room upstairs to the bin below, the vacant, irresponsible ensemble, the inscrutable determination to fulfill some strange obligation, enforced by what influence or moral unrest he could not tell, culminated in the mind of the young man in the only possible explanation:

His uncle was engaged in the unaware execution of some fixed idea.

He was responding to an uncontrollable, secret impulse, and Robert, guiding himself by the touch of his hand in order to locate his lips as close to the ear of the detective as he might, whispered with conviction:

"Somnambulist!"

"No," replied Gratz--"worse; be silent."

Amazed and wondering what could possibly be worse, and rummaging through the garret of all his unusual experiences, Robert could find nothing to correspond to this inexplicable phenomenon; and it was with a sort of superstitious distraction that he beheld his uncle discard his transient hesitation and proceed with ghostly purpose to the opening of the bin.

Advancing, Raikes placed the candle upon the bed of coals and began to unfasten the cord which secured the mouth of the bag which he carried.

Robert had never beheld anything so ghastly as his uncle's eyes, intent but unseeing; nor so frightful as his motions, direct but unintelligent, like those of a midnight marionette controlled by invisible strings.

In a few moments his efforts were successful, and the incredulous Robert beheld his uncle invert his precious burden and send a clinking, intrinsic shower of coin to the floor.

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.

Nothing, hitherto, in his life could explain the marvel, but Gratz, with trained certainty, knew that he gazed upon the disk of a dark lantern which, exposing all else to view, shielded, with its distracting flash, the object of this midnight quest.

With an assurance that indicated a definite purpose, the figure at last stood within the door of the coal bin.

At once the searching gleam began to dance hither and thither upon the floor, and finally, with unerring pause, fell directly upon the heap of glittering coin.

"Ah!" exclaimed a voice.

In its concentrated emphasis there was the unmistakable accent of certitude, of expectation gratified.

The next instant the light was placed upon the floor with a tilt that sent its rays upon the treasure, and the unknown began to collect the gold with oblivious haste and bestow it in some receptacle near-by.

Suddenly Robert felt his companion move forward noiselessly, at the same time he recognized the intimation of a detaining hand; and then he stood alone.

Scarcely had he adjusted himself to these startling conditions when he heard a sharp, metallic snap, and beheld a sudden flood of light directed upon the kneeling figure.

There was a cry of desperate amazement, the quick clink of scattering coin, and the next instant a wild, rage-distorted face shot into view.