I uttered a short cry, of which I was instantly ashamed, for Nayland Smith's voice came:--

"I startled you, eh, Petrie?"

"Smith," I said, "how long have you been standing there?"

"I only returned in time to see our Fenimore Cooper friend retreating through the window," he replied; "but no doubt you had a good look at him?"

"I had!" I answered eagerly. "It was Samarkan!"

"I thought so! I have suspected as much for a long time."

"Was this the object of our visit here?"

"It was one of the objects," admitted Nayland Smith evasively.

From some place not far distant came the sound of a restarted engine.

"The other," he added, "was this: to enable M. Samarkan to read the note which I had pinned upon the door!"

CHAPTER XXI

THE SECOND MESSAGE

"Here you are, Petrie," said Nayland Smith--and he tossed across the table the folded copy of a morning paper. "This may a.s.sist you in your study of the first Zagazig message."

I set down my cup and turned my attention to the "Personal" column on the front page of the journal. A paragraph appeared therein conceived as follows:--

ZAGAZIG-_Z_-a-g-_a_;-z:-I:-_g_;z-a,g;- A-,_z_;_i_:_G_,-z:_a_;_g_-A,z-_i_;-gz _A_;_g_aZ-_i_;_g_-:a z i g

I stared across at my friend in extreme bewilderment.

"But, Smith!" I cried, "these messages are utterly meaningless!"

"Not at all," he rapped back. "Scotland Yard thought they were meaningless at first, and I must admit that they suggested nothing to me for a long time; but the dead dacoit was the clue to the first, Petrie, and the note pinned upon the door of the house near the Oval is the clue to the second."

Stupidly I continued to stare at him until he broke into a grim smile.

"Surely you understand?" he said. "You remember where the dead Burman was found?"

"Perfectly."

"You know the street along which, ordinarily, one would approach the wharf?"

"Three Colt Street?"

"Three Colt Street, exactly. Well, on the night that the Burman met his end I had an appointment in Three Colt Street with Weymouth. The appointment was made by 'phone, from the New Louvre! My cab broke down and I never arrived. I discovered later that Weymouth had received a telegram purporting to come from me, putting off the engagement."

"I am aware of all this!"

Nayland Smith burst into a loud laugh.

"But _still_ you are fogged!" he cried. "Then I'm hanged if I'll pilot you any farther! You have all the facts before you. There lies the first Zagazig message; here is the second; and you know the context of the note pinned upon the door? It read, if you remember, 'Remove patrol from Joy-Shop neighborhood. Have a theory. Wish to visit place alone on Monday night after one o'clock.'"

"Smith," I said dully, "I have a heavy stake upon this murderous game."

His manner changed instantly; the tanned face grew grim and hard, but the steely eyes softened strangely. He bent over me, clapping his hands upon my shoulders.

"I know it, old man," he replied; "and because it may serve to keep your mind busy during hours when otherwise it would be engaged with profitless sorrows, I invite you to puzzle out this business for yourself. You have nothing else to do until late to-night, and you can work undisturbed, here, at any rate!"

His words referred to the fact that, without surrendering our suite at the New Louvre Hotel, we had gone upon a visit, of indefinite duration, to a mythical friend; and now were quartered in furnished chambers adjoining Fleet Street.

We had remained at the New Louvre long enough to secure confirmation of our belief that a creature of Fu-Manchu spied upon us there; and now we only awaited the termination of the night's affair to take such steps as Smith might consider politic in regard to the sardonic Greek who presided over London's newest and most palatial hotel.

Smith setting out for New Scotland Yard in order to make certain final arrangements in connection with the business of the night, I began closely to study the mysterious Zagazig messages, determined not to be beaten, and remembering the words of Edgar Allan Poe--the strange genius to whom we are indebted for the first workable system of deciphering cryptograms: "It may well be doubted whether human ingenuity can construct an enigma of the kind which human ingenuity may not, by proper application, resolve."

The first conclusion to which I was borne was this: that the letters comprising the word "Zagazig" were designed merely to confuse the reader, and might be neglected; since, occurring as they did in regular sequence, they could possess no significance. I became quite excited upon making the discovery that the _punctuation marks_ varied in almost every case!

I immediately a.s.sumed that these const.i.tuted the cipher; and, seeking for my key-letter, _e_ (that which most frequently occurs in the English language), I found the sign of a full-stop to appear more frequently than any other in the first message, namely ten times, although it only occurred thrice in the second. Nevertheless, I was hopeful ... until I discovered that in two cases it appeared three times _in succession!_

There is no word in English, nor, so far as I am aware, in any language, where this occurs, either in regard to _e_ or any other letter!

That unfortunate discovery seemed so wholly to destroy the very theory upon which I relied, that I almost abandoned my investigation there and then. Indeed, I doubt if I ever should have proceeded were it not that by a piece of pure guesswork I blundered on to a clue.

I observed that certain letters, at irregularly occurring intervals, were set in capital, and I divided up the message into corresponding sections, in the hope that th capitals might indicate the commencements of words. This accomplished, I set out upon a series of guesses, basing these upon Smith's a.s.surance that the death of the dacoit afforded a clue to the first message and the note which he (Smith) had pinned upon the door a clue to the second.

Such being my system--if I can honor my random attempts with the t.i.tle--I take little credit to myself for the fortunate result. In short, I determined (although _e_ twice occurred where _r_ should have been!) that the first message from the thirteenth letter, onwards to the twenty-seventh (_id est:_ _I;_g:-zagAz;i-;_g_;_-Z_,-a;-_g_azi;-) read:--

_"Three Colt Street."_

Endeavoring, now, to eliminate the _e_ where _r_ should appear, I made another discovery. The presence of a letter in _italics_ altered the value of the sign which followed it!

From that point onward the task became child's-play, and I should merely render this account tedious if I entered into further details.

Both messages commenced with the name "Smith" as I early perceived, and half an hour of close study gave me the complete sentences, thus:--

1. _Smith pa.s.sing Three Colt Street twelve-thirty Wednesday._

2. _Smith going Joy-Shop after one Monday._

The word "Zagazig" was completed, always, and did not necessarily terminate with the last letter occurring in the cryptographic message.

A subsequent inspection of this curious code has enabled Nayland Smith, by a process of simple deduction, to compile the entire alphabet employed by Dr. Fu-Manchu's agent, Samarkan, in communicating with his awful superior. With a little patience, any one of my readers my achieve the same result (and I should be pleased to hear from those who succeed!).

This, then was the outcome of my labors; and although it enlightened me to some extent, I realized that I still had much to learn.

The dacoit, apparently, had met his death at the very hour when Nayland Smith should have been pa.s.sing along Three Colt Street--a thoroughfare with an unsavory reputation. Who had killed him?