OUGLAS 109 293 5 37 BIRLSTONE 26
BIRLSTONE 9 47 171

"What do you make of it, Holmes?"

"It is obviously an attempt to convey secret information."

"But what is the use of a cipher message without the cipher?"

"In this instance, none at all."

"Why do you say 'in this instance'?"

"Because there are many ciphers which I would read as easily as I do the
apocrypha of the agony column: such crude devices amuse the intelligence
without fatiguing it. But this is different. It is clearly a reference
to the words in a page of some book. Until I am told which page and
which book I am powerless."

"But why 'Douglas' and 'Birlstone'?"

"Clearly because those are words which were not contained in the page in
question."

"Then why has he not indicated the book?"

"Your native shrewdness, my dear Watson, that innate cunning which is
the delight of your friends, would surely prevent you from inclosing
cipher and message in the same envelope. Should it miscarry, you are
undone. As it is, both have to go wrong before any harm comes from it.
Our second post is now overdue, and I shall be surprised if it does
not bring us either a further letter of explanation, or, as is more
probable, the very volume to which these figures refer."

Holmes's calculation was fulfilled within a very few minutes by the
appearance of Billy, the page, with the very letter which we were
expecting.

"The same writing," remarked Holmes, as he opened the envelope, "and
actually signed," he added in an exultant voice as he unfolded the
epistle. "Come, we are getting on, Watson." His brow clouded, however,
as he glanced over the contents.

"Dear me, this is very disappointing! I fear, Watson, that all our
expectations come to nothing. I trust that the man Porlock will come to
no harm.

"DEAR MR. HOLMES [he says]:

"I will go no further in this matter. It is too dangerous--he suspects
me. I can see that he suspects me. He came to me quite unexpectedly
after I had actually addressed this envelope with the intention of
sending you the key to the cipher. I was able to cover it up. If he had
seen it, it would have gone hard with me. But I read suspicion in his
eyes. Please burn the cipher message, which can now be of no use to you.

"FRED PORLOCK."

Holmes sat for some little time twisting this letter between his
fingers, and frowning, as he stared into the fire.

"After all," he said at last, "there may be nothing in it. It may be
only his gui