He turned and quitted the office, carefully closing the door behind him. Three seconds later he reopened it, and peering in, was in time to see the boy knock upon the private door. A little wicket, or movable panel, was let down, the card of John Henry Smith was pa.s.sed through to someone unseen, and the wicket was reclosed!

The boy turned and met the wrathful eye of the detective. Bristol reentered, closing the door behind him.

"See here, young fellow," said he, "I don't stand for those tricks!

Why didn't you tell me Mr. Knowlson was in?"

"I'm very sorry, sir!"--the boy quailed beneath his glance--"but he won't see any one who hasn't an appointment."

"Is there someone with him, then?"

"No."

"Well, what's he doing?"

"I don't know, sir; I've never been in to see!"

"What! never been in that room?"

"Never!" declared the boy solemnly. "And I don't mind telling you," he added, recovering something of his natural confidence, "that I am leaving on the 31st. This job ain't any use to me!"

"Too much work?" suggested Bristol.

"No work at all!" returned the boy indignantly. "I'm just here for a blessed buffer, that's what I'm here for, a buffer!"

"What do you mean?"

"I just have to sit here and see that n.o.body gets into that office. Lively, ain't it? Where's the prospects?"

Bristol surveyed him thoughtfully.

"Look here, my lad," he said quietly; "is that door locked?"

"Always," replied the boy.

"Does Mr. Knowlson come to that shutter when you knock?"

"Yes."

"Then go and knock!"

The boy obeyed with alacrity. He rapped loudly on the door, not noticing or not caring that the visitor was standing directly behind him. The shutter was lowered and a grizzled, bearded face showed for a moment through the opening.

Bristol leant over the boy and pushed a card through into the hand of the man beyond. On this occasion it did not bear the legend "John Henry Smith," but the following--

CHIEF INSPECTOR BRISTOL C.I.D.

NEW SCOTLAND YARD

"Good afternoon, Mr. Knowlson," said the detective dryly. "I want to come in!"

There followed a moment of silence, from which Bristol divined that he had blundered upon some mystery, possibly upon a big case; then a key was turned in the lock and the door thrown open.

"Come right in, Inspector," invited a strident voice. "Carter, you can go home."

Bristol entered warily, but not warily enough. For as the door was banged upon his entrance he faced around only in time to find himself looking down the barrel of a Colt automatic.

With his back to the door which contained the wicket, now reclosed, stood the man with the bearded face. The revolver was held in his left hand; his right arm terminated in a bandaged stump. But without that his steel-gray eyes would have betrayed him to the detective.

"Good G.o.d!" whispered Bristol. "It's Earl Dexter!"

"It is!" replied the cracksman, "and you've looked in at a real inconvenient time! My visitors mostly seem to have that knack.

I'll have to ask you to stay, Inspector. Sit down in that chair yonder."

Bristol knew his man too well to think of opening any argument at that time. He sat down as directed, and ignoring the revolver which covered him all the time, began coolly to survey the room in which he found himself. In several respects it was an extraordinary apartment.

The only bright patch in the room was the shining disc upon the ceiling; and the detective noted with interest that this marked the position of an arrangement of mirrors. A white-covered table, entirely bare, stood upon the floor immediately beneath this mysterious apparatus. With the exception of one or two ordinary items of furniture and a small hand lathe, the office otherwise was unfurnished. Bristol turned his eyes again upon the daring man who so audaciously had trapped him--the man who had stolen the slipper of the Prophet and suffered the loss of his hand by the scimitar of an Hashishin as a result. When he had least expected to find one, Fate had thrown a clue in Bristol's way. He reflected grimly that it was like to prove of little use to him.

"Now," said Dexter, "you can do as you please, of course, but you know me pretty well and I advise you to sit quiet."

"I am sitting quiet!" was the reply.

"I am sorry," continued Dexter, with a quick glance at his maimed arm, "that I can't tie you up, but I am expecting a friend any moment now."

He suddenly raised the wicket with a twitch of his elbow and, without removing his gaze from the watchful detective, cried sharply--

"Carter!"

But there was no reply.

"Good; he's gone!"

Dexter sat down facing Bristol.

"I have lost my hand in this game, Mr. Bristol," he said genially, "and had some narrow squeaks of losing my head; but having gone so far and lost so much I'm going through, if I don't meet a funeral!

You see I'm up against two tough propositions."

Bristol nodded sympathetically.

"The first," continued Dexter, "is you and Cavanagh, and English law generally. My idea--if I can get hold of the slipper again--oh! you needn't stare; I'm out for it!--is to get the Antiquarian Inst.i.tution to ransom it. It's a line of commercial speculation I have worked successfully before. There's a dozen rich highbrows, cranks to a man, connected with it, and they are my likeliest buyers--sure. But to keep the tone of the market healthy there's Ha.s.san of Aleppo, rot him! He's a dangerous customer to approach, but you'll note I've been in negotiation with him already and am still, if not booming, not much below par!"

"Quite so," said Bristol. "But you've cut off a pretty hefty chew nevertheless. They used to call you The Stetson Man, you used to dress like a fashion plate and stop at the big hotels. Those days are past, Dexter, I'm sorry to note. You're down to the skulking game now and you're nearer an advert for Clarkson than Stein-Bloch!"

"Yep," said Dexter sadly, "I plead guilty, but I think here's Carneta!"

Bristol heard the door of the outer office open, and a moment later that upon which his gaze was set opened in turn, to admit a girl who was heavily veiled, and who started and stood still in the doorway, on perceiving the situation. Never for one unguarded moment did the American glance aside from his prisoner.

"The Inspector's dropped in, Carneta!" he drawled in his strident way. "You're handy with a ball of twine; see if you can induce him to stay the night!"

The girl, immediately recovering her composure, took off her hat in a businesslike way and began to look around her, evidently in search of a suitable length of rope with which to fasten up Bristol.