“I will go no further in this matter. It is too dangerous—hesuspects me. I can see that he suspects me. He came to me quiteunexpectedly after I had actually addressed this envelope with theintention of sending you the key to the cipher. I was able to coverit up. If he had seen it， it would have gone hard with me. But I readsuspicion in his eyes. Please burn the cipher message， which cannow be of no use to you.
“FRED PORLOCK.”
Holmes sat for some little time twisting this letter between hisfingers， and frowning， as he stared into the fire.
“After all，” he said at last， “there may be nothing in it. It may beonly his guilty conscience. Knowing himself to be a traitor， he mayhave read the accusation in the other’s eyes.”
“The other being， I presume， Professor Moriarty.”
“No less！ When any of that party talk about ‘He’ you knowwhom they mean. There is one predominant ‘He’ for all of them.”
“But what can he do？”
“Hum！ That’s a large question. When you have one of the firstbrains of Europe up against you， and all the powers of darkness athis back， there are infinite possibilities. Anyhow， Friend Porlockis evidently scared out of his senses—kindly compare the writingin the note to that upon its envelope； which was done， he tells us，before this ill-omened visit. The one is clear and firm. The otherhardly legible.”
“Why did he write at all？ Why did he not simply drop it？”
“Because he feared I would make some inquiry after him in thatcase， and possibly bring trouble on him.”
“No doubt，” said I. “Of course.” I had picked up the originalcipher message and was bending my brows over it. “It’s prettymaddening to think that an important secret may lie here on thisslip of paper， and that it is beyond human power to penetrate it.”
Sherlock Holmes had pushed away his untasted breakfast andlit the unsavoury pipe which was the companion of his deepestmeditations. “I wonder！” said he， leaning back and staring atthe ceiling. “Perhaps there are points which have escaped yourMachiavellian intellect. Let us consider the problem in the light ofpure reason. This man’s reference is to a book. That is our point ofdeparture.”
“A somewhat vague one.”
“Let us see then if we can narrow it down. As I focus my mindupon it， it seems rather less impenetrable. What indications havewe as to this book？”
“None.”
“Well， well， it is surely not quite so bad as that. The ciphermessage begins with a large 534， does it not？ We may take it as aworking hypothesis that 534 is the particular page to which thecipher refers. So our book has already become a large book， whichis surely something gained. What other indications have we as tothe nature of this large book？ The next sign is C2. What do youmake of that， Watson？”
“Chapter the second， no doubt.”
“Hardly that， Watson. You will， I am sure， agree with me that ifthe page be given， the number of the chapter is immaterial. Alsothat if page 534 finds us only in the second chapter， the length ofthe first one must have been really intolerable.”
“Column！” I cried.
“Brilliant， Watson. You are scintillating this morning. If it is notcolumn， then I am very much deceived. So now， you see， we beginto visualize a large book printed in double columns which areeach of a considerable length， since one of the words is numberedin the document as the two hundred and ninety-third. Have wereached the limits of what reason can supply？”
“I fear that we have.”
“Surely you do yourself an injustice. One more coruscation， mydear Watson—yet another brain-wave！ Had the volume been anunusual one， he would have sent it to me. Instead of that， he hadintended， before his plans were nipped， to send me the clue in thisenvelope. He says so in his note. This would seem to indicate thatthe book is one which he thought I would have no difficulty infinding for myself. He had it—and he imagined that I would haveit， too. In short， Watson， it is a very common book.”
“What you say certainly sounds plausible.”
“So we have contracted our field of search to a large book，printed in double columns and in common use.”
“The Bible！” I cried triumphantly.
“Good， Watson， good！ But not， if I may say so， quite goodenough！ Even if I accepted the compliment for myself I couldhardly name any volume which would be less likely to lie at theelbow of one of Moriarty’s associates. Besides， the editions ofHoly Writ are so numerous that he could hardly suppose that twocopies would have the same pagination. This is clearly a bookwhich is standardized. He knows for certain that his page 534 willexactly agree with my page 534.”
“But very few books would correspond with that.”
“Exactly. Therein lies our salvation. Our search is narroweddown to standardized books which anyone may be supposed topossess.”
“Bradshaw！”
“There are difficulties， Watson. The vocabulary of Bradshawis nervous and terse， but limited. The selection of words wouldhardly lend itself to the sending of general messages. We willeliminate Bradshaw. The dictionary is， I fear， inadmissible for thesame reason. What then is left？”
“An almanac！”
“Excellent， Watson！ I am very much mistaken if you have nottouched the spot. An almanac！ Let us consider the claims ofWhitaker’s Almanac. It is in common use. It has the requisitenumber of pages. It is in double column. Though reserved in itsearlier vocabulary， it becomes， if I remember right， quite garruloustowards the end.” He picked the volume from his desk. “Hereis page 534， column two， a substantial block of print dealing， Iperceive， with the trade and resources of British India. Jot downthe words， Watson！ Number thirteen is ‘Mahratta.’ Not， I fear， avery auspicious beginning. Number one hundred and twenty-sevenis ‘Government’； which at least makes sense， though somewhatirrelevant to ourselves and Professor Moriarty. Now let us try again.
What does the Mahratta government do？ Alas！ the next word is‘pig’s-bristles.’ We are undone， my good Watson！ It is finished！”