“Which is likely?”

By way of reply he handed me a letter marked “Private.”  It was dated a week ago, and signed “Yours faithfully, Horace Wragge.”

“He heard of me, you see, through Captain Anderson,” the doctor explained modestly, as though his fame were not almost world-wide; “you remember that Indian obsession case—­”

I read the letter.  Why it should have been marked private was difficult to understand.  It was very brief, direct, and to the point.  It referred by way of introduction to Captain Anderson, and then stated quite simply that the writer needed help of a peculiar kind and asked for a personal interview—­a morning interview, since it was impossible for him to be absent from the house at night.  The letter was dignified even to the point of abruptness, and it is difficult to explain how it managed to convey to me the impression of a strong man, shaken and perplexed.  Perhaps the restraint of the wording, and the mystery of the affair had something to do with it; and the reference to the Anderson case, the horror of which lay still vivid in my memory, may have touched the sense of something rather ominous and alarming.  But, whatever the cause, there was no doubt that an impression of serious peril rose somehow out of that white paper with the few lines of firm writing, and the spirit of a deep uneasiness ran between the words and reached the mind without any visible form of expression.

“And when you saw him—?” I asked, returning the letter as the train rushed clattering noisily through Clapham Junction.

“I have not seen him,” was the reply.  “The man’s mind was charged to the brim when he wrote that; full of vivid mental pictures.  Notice the restraint of it.  For the main character of his case psychometry could be depended upon, and the scrap of paper his hand has touched is sufficient to give to another mind—­a sensitive and sympathetic mind—­clear mental pictures of what is going on.  I think I have a very sound general idea of his problem.”

“So there may be excitement, after all?”

John Silence waited a moment before he replied.

“Something very serious is amiss there,” he said gravely, at length.  “Some one—­not himself, I gather,—­has been meddling with a rather dangerous kind of gunpowder.  So—­yes, there may be excitement, as you put it.”

“And my duties?” I asked, with a decidedly growing interest.  “Remember, I am your ‘assistant.’”

“Behave like an intelligent confidential secretary.  Observe everything, without seeming to.  Say nothing—­nothing that means anything.  Be present at all interviews.  I may ask a good deal of you, for if my impressions are correct this is—­”

He broke off suddenly.

“But I won’t tell you my impressions yet,” he resumed after a moment’s thought.  “Just watch and listen as the case proceeds.  Form your own impressions and cultivate your intuitions.  We come as ordinary visitors, of course,” he added, a twinkle showing for an instant in his eye; “hence, the guns.”