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 guilty conscience. Knowing himself to be a
traitor, he may have 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 know whom
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 first
brains of Europe up against you, and all the powers of darkness