"Exactly, my dear Watson! Hence the extreme importance of
Porlock. Led on by some rudimentary aspirations towards right,
and encouraged by the judicious stimulation of an occasional
ten-pound note sent to him by devious methods, he has once or
twice given me advance information which has been of value--that
highest value which anticipates and prevents rather than avenges
crime. I cannot doubt that, if we had the cipher, we should find
that this communication is of the nature that I indicate."

Again Holmes flattened out the paper upon his unused plate. I
rose and, leaning over him, stared down at the curious
inscription, which ran as follows:

534 C2 13 127 36 31 4 17 21 41 DOUGLAS 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.