'He said that she wore a coat with a deep cape, and that she rested one arm upon the case.'

'Well, I did wonder what the woman's dress had to do with it. 'Gad, but you questioned those people until I began to feel sorry for them.

What figure, now, is the dress likely to cut?'

I laughed.

'In this case let us suppose that the young woman is one of the gang.'

'Oh!'

'And let us fancy that while she peered at the pink topaz--you remember Lausch told us that she excused her nearness by saying that she was very near-sighted?'

'That's so.'

'Well, while looking at the gems, with her face bent over the case, one arm upon the edge, and with the voluminous cape outspread, what is to prevent her using the other hand and arm to draw a diamond point slowly and heavily along the gla.s.s, close to the metal?'

'By Jove! what indeed?'

'And why may not this act be repeated, three or four times, say, by the same woman, slightly changed as to dress, as she could have been?

Lausch, you recall, accosted her.'

'Yes.'

When Dave grew laconic I knew him to be almost convinced.

'You will recall how each of the attendants remembered one or more instances of persons lingering long near the gems, or crowding so close as to attract the attention of some of them.'

'Umph!'

'And Lausch distinctly remembered how a good-natured guard came to his aid just as he was about to close his exhibits, and stood with his back to the case, and his arms carelessly outspread upon the edge chaffing with a group of late sight-seers, and keeping them from annoying him (Lausch) while he made things secure. Now I don't say that it was done, but I can see how that guard might have played into the hands of the gang, who might have been at hand three or four strong. Observe, the cases were high at the inner sides and shallow at the front, and while the top sheet of gla.s.s, for purposes of display, was a large one, those forming the outer side were small and set into stout bronzed squares not to exceed seven inches in depth and ten in length. Now, we will note that the back of the case, besides being higher than the front, is not of gla.s.s, but of wood, to admit of the use of a mirror for lining, and to double the show and glitter of the gems.'

'Upon--my--word!'

'Now let us suppose our guard as standing before the case and directly in front of the diamonds. He is facing outward, and before him, hovering close, are some others, two or three, or more. On the other sides of the octagonal pavilion the other a.s.sistants are busy "closing up." Lausch in person presides at the small safe in the centre of the place. Now, while he is busy, with his eyes averted for a moment, a hand thrust under the outstretched arm of the guard may gently press something adhesive against the already cut gla.s.s and pull it out, and soon, when Lausch bends down to open the safe, or to place some article therein, the hand draws out the little tray of gems; it was small, and could have been concealed under one of those wraps thrown conveniently across the arm. Now, a little ruse to subst.i.tute the false gems and replace the gla.s.s under the guard's concealing arm, and the thing is done. If it all happened at the closing hour, when the big building was shadowy and one could see clearly only a short distance, when every exhibitor was occupied with his own, and visitors, for the most part, were intent upon reaching the nearest exit--it was bound to succeed. Of course this is all theory, but----'

'It's the explanation of that theft, or I'm a sinner!' cried Dave, jumping up and beginning to pace the floor nervously. 'Carl, old man, I'll never chaff your "b.u.mp of imagination," after to-day. I'm ready to begin work on just that theory.'

'Steady, steady, Dave.'

'All right, sir; at least we can make a beginning--we can find that guard.'

'How?'

'Take his description from Lausch--find out who was detailed here----'

I put up my hand, and he stopped--staring.

'Dave, there is not a Columbian guard on the force who would, or could, have played that part--if it was played. It was simply one of the band wearing a guard's uniform.'

My friend sat down opposite me, and for some time not a word pa.s.sed between us. Then he took up his notebook, and, drawing a small table toward us, said:

'Let's go over the ground slowly, and see if there is anything here to corroborate your theory, or to point to any other conclusion.'

And now I knew that Dave was fixed, so far as his opinions were concerned, and that while he might declare himself convinced by my wisdom, he had been all the time simply establishing his own convictions, and that he was now ready for earnest work.

It was some time before we came out from the superintendent's little inner sanctum, but we were now quite ready to begin our campaign; and when we were given _carte blanche_ as to methods, and were promised as many men as we might need for the work, we could ask for nothing more, or better.

Our first demand was peremptory. There must be no publicity; no word of the robbery must reach the vigilant reporters who were everywhere in search of news.

Next, we caused an accurate description of Greenback Bob to be sent to all the gates and different districts, with orders for an instant report of the fact should he be seen, and that once seen he must be constantly shadowed.

Before we left the place we had arranged with Lausch to put a man of our own choosing into the pavilion, whose business it would be to keep constant watch over his people. For while he was ready to vouch for their honesty, we were not; rather, we were not willing to let any possibility of a clue escape us. A second man was placed where he could cultivate these people, and as much as possible outside of business hours. Not that we expected much from this, for we had seen no slightest sign of dishonesty among these people, who seemed to shun all society and to have no acquaintances outside their own pavilion.

After considering long, we decided not to bring the name of Delbras into the case, or to attempt to set any watch upon him in the regular way. To 'locate' Delbras should be our own especial work, and to freshen our memories we reviewed the information furnished our chief by the French commissaire.

So far as was known there was no picture of him extant, and the French report described him about as follows:

'Nationality, French; age, probably about thirty to thirty-three years; height, six feet, or nearly; weight, one hundred and seventy-five pounds, approximate; figure good; square shoulders, military air; features, regular; thin lipped; chin sharply pointed; wears at times heavy beard, at others moustache and goatee; eyes dark, called black; hair same, heavy, and sometimes worn quite long; hands well kept, with long slender fingers; speaks English perfectly, accomplished, etc.; a small triangular scar upon temple close to roots of hair. Known to have been in Paris and London in early winter, and to have crossed to New York about January 1st. Returned to Paris some time in March, and crossed last to New York in early May by steamer _Normandie_.'

'Well,' had been Dave's comment as we reperused this summary of M.

Delbras, 'he may disguise himself in many ways, but he can't change his height very much, nor the colour of his eyes, nor his "regular features"'--Dave's features were not strictly regular, and it was a weakness of his always to resent this descriptive phrase--'nor his slim fingers, nor the scar on his temple close to the roots of the hair.'

We had spent a long morning in the rooms of the Secret Service Bureau, and as we were about to take leave, with but a step between us and the outer door, it was hastily opened and a guard entered, followed by two people whom I recognised as Farmer and Mrs. Camp. With a backward step and a quick glance at Dave, I turned and deliberately seated myself.

The only occupants of the outer office at the moment of their entry were the officer in command, who had just accompanied us from the inner office, and the subordinate who was in charge of this outer office, where complaints were received and first hearings granted.

I had drawn back quickly, but the eye of Mrs. Camp was still keen, though she looked a trifle subdued.

'The good land!' she e.j.a.c.u.l.a.t.ed, catching at her husband's arm.

'Here's one of 'em now, Camp! They've caught him, anyhow!'

The words furnished Dave with a clue to the situation, and he dropped into a chair beside me, and, after one droll look in my direction, gave himself up to a fit of silent mirth.

Meantime the guard had advanced with dignity and announced to the officer at the desk:

'This man has a complaint to bring, sir.'

'Wait!' It was Mrs. Camp, standing determinedly near the door of entrance, who spoke. 'Afore you make a complaint, Adam Camp, about a raskil that ain't here, s'pose you jest make sure that this here one that is here in our midst don't git away.'

CHAPTER VI.

A CRIMINAL HUNT.

Now, I had told the officer in command my belief and suspicions concerning the counterfeit business which I believed was going on about us, and had been told that two of the counterfeit bills had already been brought to his notice and captured within the week; and Dave had insisted upon his hearing the story of my absurd arrest by the guards, and now it only needed a look from me, and the sight of Dave's convulsed face, to make the situation plain to him. He stepped forward, but before he could speak a new thought had darted into Dame Camp's active mind.