III
After Martin Hewitt had rushed off to St. Augustine's Hospital with thekey, the envelope, and the cypher I had brought him, I heard nothing ofhim till dusk fell--about six. Then I received this telegram:--
/# "Cypher read. Most interesting case. If you can spare an hour be outside 120 Broad Street at six thirty.--Hewitt."#/
I had to be at my office between eight and nine, and to keep Hewitt'sappointment I should probably have to sacrifice my dinner. But I wasparticularly curious to know the meaning of that cypher, and just ascurious to know how it could be read; and, moreover, I knew that anycase that Hewitt called interesting would probably be interesting abovethe common. So I took my hat and sought a cab.
I was first at the meeting-place--indeed, a little before my time. No.120 Broad Street was a great new building of offices, most, if not all,closed at this time--a fact indicated by the shutting of one of thehalves of the big front door, where a char-woman was sweeping the stepsunder the board which announced that offices were to be let. I waitednearly a quarter of an hour, and then at last a hansom stopped anddeposited Hewitt and another older gentleman before me.
"Hope we haven't kept you waiting, Brett," Hewitt said. "This is Mr.Bell, of Kingsley, Bell and Dalton; it took me a little longer than Iexpected to reach him. His offices are shut, and the clerks all gone,but we are going to turn up the lights for a bit. The lift man is gonetoo, I expect, so we shall have a good long stair-climb."
As to the lift man Hewitt was right, and during our long climb Ireceived, briefly, an account of the loss Mr. Bell's firm had suffered."I have told Mr. Bell," Hewitt said, "that it was you who happenedacross the key in such an odd fashion, and when I wired I was sure hewould be glad to let you see the upshot of your strange bit of luck. Iwas also pretty sure that you would like to see it, too. For I reallybelieve that this case--which I confess seemed pretty near hopeless afew hours ago--is coming to an issue now, and here."
"Did you get any information out of the man in the hospital?" I asked.
"Not a scrap," Hewitt replied. "He was still insensible, and though Isaw his clothes, and they told me a good deal about the gentleman'spersonal habits--which are not dazzlingly noble, to put it mildly--theytold me nothing else whatever, except that he had recently been knockeddown in the mud, which I knew already. But the cypher has told mesomething, as I will explain presently."
By this time we had reached the high floor in which the offices stood,and Mr. Bell, all wonder and pale agitation, unlocked the outer door,and turned on the electric light.
"Now," cried Hewitt, "show me your ventilators!"
There were some, it seemed, in the top panes of the windows, but thesewere not what Hewitt wanted. There were others in the form of uprightchambers or flues, made of metal, and painted the same colour as thewalls about them. They rose from the floor in corners and wall angles,and could be shut or opened by means of lids over their upper ends.These were more to Hewitt's mind, and he went about from one to another,groping under the lids, and poking down into the flues with awalking-stick. There was a wire-grating, or diaphragm, it seemed, ineach of them, two or three feet down, and we could hear the end of thestick raking on this at each investigation. One after another of theseventilators Hewitt examined, till he had examined them all, in outer andinner rooms, without result; and I could see that he was disappointed.
"There must be another somewhere," he said, and hunted afresh.
But plainly he had tried them all, and now he could do no more than trythem all again, with as little result.
"It _is_ a ventilator," he said, positively. "Unless----" he broke offthoughtfully and stood silent for a few moments. "Ah! of course!" heresumed presently. "We'll send for the housekeeper and a candle. Whichis the nearest empty office--the nearest office to let? Is there one onthis floor?"
"I think not," Mr. Bell answered. "But there's one on the floor below,just opposite the lift--I see the bill on the door every day as I comeup."
"We'll try that, then. I'll rake out every ventilator in this palatialedifice before I'll call myself beaten. Come, call the housekeeper. Isthere a speaking tube? Tell him to bring a light."
The housekeeper came, wonderingly, with a watch-man's oil-lantern, andwe all went to the floor below. Opposite the lift was a glass door fromwhich a bill had recently been torn.
"Why, it's let!" said Mr. Bell.
"Yes, sir," assented the housekeeper. "Let a day or two ago to a Mr.Catherton Hunt. Or, at least, a deposit was paid."
"But see--the door's not locked," Hewitt observed, pushing it open. "Ithink we'll trespass on Mr. Catherton Hunt's new offices, since theyseem quite empty, and he hasn't taken possession. Come--ventilators!"
It was a small office--an outer room of moderate size, and one smallerinner room. Hewitt at once attacked the ventilators in the largerapartment--there were two of them--but retired disappointed from each.There was one ventilator only in the small room. Hewitt tilted the lid,which was at about the level of his eyes, thrust in his hand, and drewforth a bundle of folded papers; thrust in his hand again and drew forthanother bundle; did it again, and drew forth more!
Mr. Bell fell upon the first bundle almost as a dog falls upon a bone;and now he snatched eagerly at each successive paper or bundle, tillHewitt raked the grating with his stick, and declared that there were nomore. "Is that all?" he asked.
Mr. Bell went tremblingly from paper to paper, and, at last, said thathe believed it really was. "I can verify it by the list upstairs," headded, "if you are sure there are no more."
"No more," repeated Hewitt, rattling his stick in the ventilator again."Let us go and verify, by all means."
We sent the puzzled housekeeper away, and returned to the office above,and presently Mr. Bell, now beginning so far to recover from hisamazement as to express incoherent gratitude, reported that the bondswere correct and complete to the last and least.
"Very well," said Hewitt, "then my part of the business is done, thoughI must say I've had luck, or rather, Brett has had it for me. But thepolice must come on now. I think, Mr. Bell, we'll go along to ScotlandYard when we leave here. They'll be wanting to see Mr. Catherton Hunt, Iexpect, whoever he is--and somebody in your office, too, if I'm notsadly mistaken."
"Who?" gasped Mr. Bell.
"That, perhaps, you can help to point out. See here--do you know whosefigures they are?" and Hewitt produced the small slip of papercontaining the cypher.
"They're very small," remarked Mr. Bell, putting on his glasses; "verysmall indeed; but I think--why they're Henning's, I do believe!"
"Ah! one or two other little things seemed to point that way. Henning isyour correspondence clerk, I believe, and I expect this thin little slipis a specimen of your typewriter paper. Have you any of his writtenfigures for comparison?"
"Well no--I hardly think--you see he typewrites his letters, andalthough I know his writing very well I can't at the moment put my handon any figures of his."
"Never mind--it's mere matter of curiosity; the police will ask himquestions in the morning. What _I_ believe has happened is this. Ourfriend Henning--if he's the man--has a friend outside a great dealcleverer than himself--though he would seem to have his share ofcunning, too. Between them they resolved to rob you in the way they havedone--temporarily. Henning was to take advantage of his position in thatlittle inner room to get at the safe some day when it was open and whenyou were engaged in your own private inner room with a client, soleaving the safe unwatched. He was provided with a spare patent padlockand key, of the sort you used on that black box, and his confederate haddrilled him in the trick of breaking that particular sort of padlockopen, with other spare specimens. He got his opportunity this morning."
"Only this morning?"
"This morning, I think, else we should never have got these bonds back,nor even have heard of them again. I think you said you were engagedwith a client for half an hour?"
"Yes, from about half-past ten to eleven."
&n
bsp; "That was his chance, and he took it. He broke the padlock, took out thebonds, substituted the dummies he had already prepared in his own desk,and locked the box again with the new padlock. Meantime Hunt had paid adeposit, pending references, on the office below--the nearest emptyroom. Of course, he wouldn't get the key until the tenancy was finallyaccepted--which he never intended it should be. But he easily arrangedto have the door left unlocked for a day or two, on some convenientexcuse--arranging decorations, or what not. And the bill was taken down,so that prospective and prospecting tenants were kept away. The bondsbeing stolen, Henning took the first opportunity of carrying them to theempty office--probably piecemeal--a thing he could easily manage almostunder your nose, before you were aware of your loss. There he was toconceal them, either in the chimney, under the boards, or in theventilator, as he might find convenient--and he found the ventilatormost convenient. Then he was to apprise his confederate of the fact thatthe robbery had been effected in order that Hunt might come and quietlyfetch the plunder away. The message was to take an ingenious form. Huntwas to have a fellow waiting about in the street, and as soon as Henningcould get out--say to lunch--he was just to _send the key_ by thismessenger--the key with which he had locked the new padlock on the blackbox. You see the advantages of that simple arrangement. First, the key,which is evidence, is got rid of in a safe and effectual way--a thingthat couldn't be done as well by merely flinging it away on or near thepremises, where it might be found. Next, the message is perfectlysecret--the messenger could never guess what the key meant, nor couldany other person not in the confederate's confidence. And, at the sametime, the key tells all that is necessary; the robbery has beeneffected--come and remove the plunder.
"But something unforeseen happens. No sooner are the bonds stolen andsafely hidden than you go to the box, find something wrong with thelock, break it open and discover the loss. This was a thing that theytrusted would not happen till after the bonds were safely got away.More, I am sent for, the clerks are kept in from lunch, and so on.Henning gets into a funk, and resolves to send a message of specialurgency to his confederate. For that purpose he uses a cypher which thetwo have agreed upon--the most ingenious cypher I have ever seen usedfor the purpose. He doesn't wish to make his message any moreconspicuous than he need, so he writes his cypher on this scrap of paperand rolls it inside the key--probably another expedient agreed upon incase of necessity. Then the key goes into an envelope, for greatersecurity of the cypher message, and the messenger gets it when Henningis at last released for lunch. What happened to the message we know; andhere it is.
"Now I will not weary you with a detailed account of the different waysin which I attacked this cypher, but I will take the shortest possiblecut to the true interpretation. A very short examination of thecryptogram shows that while no number is included above 23, the numbers,in their relative frequency, roughly agree with the relative frequencyof the corresponding letters of the alphabet, _a_ for 1, _b_ for 2, andso on."
Here I handed Hewitt the pencilled note I had made at the hospital, withletters substituted for the figures, thus:--_i, h, n, d, t, r, e, i; o,s, t, 0, c, i, h, e; c, w, 0, 0, e, m, n, s; s, t, 0, 0, 0, 0, f, a; e,t, 0, 0, 0, 0, c, v; a, o, 0, 0, 0, 0, r, e; a, h, t, k, r, i, e, t; l,e, w, n, n, a, a, t._
Hewitt took the paper and went on. "If that were all the thing would bechildishly simple. But you will see that we seem as far from thesolution as ever; for the letters as they stand mean nothing, though infact they are in normal relative frequency; so that if they mean otherletters, all the rules are upset, and we are at a standstill. I admitthat for a long time the thing bothered me. But a peculiarity struck me.Not only were the figures, or letters, disposed in groups of _eight_,but there were also _eight_ such groups--sixty-four altogether. What didthat suggest? What but a chessboard?"
"A chessboard?" I queried.
"Just so--a chessboard. Eight squares each way--sixty-four altogether.So I drew a rough representation of a chessboard, and set out theletters on it, in their order, like this:--
i h n d t r e i o s t O c i h e c w 0 0 e m n s s t 0 o o 0 f a e t 0 o o 0 c v a o 0 o o 0 r e a h t k r i e t l e w n n a a t
"Now, there was my chessboard with my letters on it. I tried readingthem downward, across, upward and diagonally, in the direction of themoves of different chess pieces--king, queen, rook and bishop. Nothingcame of that, whatever I did; the thing was as unreadable as ever. Butthere remained one chess-move to try--the eccentric move of the knight;the move of one square forward, backward or sideways, and then onesquare diagonally, or, as it has sometimes been more conciselyexpressed, the move to the next square but one of a different colourfrom that on which it rests. I tried the knight's move, and I read thecypher.
"I began at the top left-hand corner, just as one does in reading abook. I read the moves downward--_i_ to _w_, _e_ and _h_, and found thatled to nothing. So I took the one alternative move, and, with a littleconsideration, skipped along from _i_ to _t_ in the second line ofsquares, _t_ in the top line, _h_ in the second line, _e_ in the third,_r_ in the top and _e_ in the second. That gave me an idea. There werethe letters _i, t, t_, followed by the word _here_. I tried backfrom the _i_ again, and taking in the reverse order the _w, e_ and _h_which I had first given up, I read my own name, as you can see it, fromthe _h_ on the bottom line but one, moving upward. So I had the words_Hewitt here_. I need not carry you through all the steps, which willnow be plain enough to you. But I found that the message actually beganin the _right_-hand corner, and read thus, the noughts counting fornothing--
"_'Invent loss disc take at once Martin Hewitt here fear watch.'_
"The noughts were plainly merely inserted to fill in unneeded squares,and keep the rest of the figures in their proper relative places whenthe cypher was written in line. At first I was a little puzzled tounderstand what seemed to be the first word _invent_. But it was quiteclear that _loss disc_ meant 'loss discovered,' so I concluded that herein the beginning was a contraction also, and that _in_ was a separateword. In that case _vent_ could be a contraction for no other word but'ventilator,' in accordance with the sense of the words. So I concludedthat the meaning of the whole sentence was simply this: 'The plunder isin the ventilator, the loss is discovered, take away the booty at once;Martin Hewitt is here, and I fear I may be watched.' There is thereading, and our little adventure this evening is what it has led to.
"Of course, the confederate wouldn't go groping about the squares sopainfully as I have had to do. To him the reading would be simpleenough, for the order of the moves would be preconcerted. Each of theconspirators would have, as a guide, both to reading and writing thecypher, a drawn set of squares, numbered in the order of the moves--1where we have the _i_, 2 where we have the _n_, 3 where we have the _v_,and so on. With that before him, either reading or writing in thisextraordinary cryptogram would be easy and quick enough. And now forScotland Yard!"