Sherlock Holmes drew a long breath, and wiped the perspiration from his

forehead. “I should have more faith,” he said; “I ought to know by this time

that when a fact appears to be opposed to a long train of deductions, it

invariably proves to be capable of bearing some other interpretation. Of the two

pills in that box one was of the most deadly poison, and the other was entirely

harmless. I ought to have known that before ever I saw the box at all.”

 

This last statement appeared to me to be so startling, that I could hardly

believe that he was in his sober senses. There was the dead dog, however, to

prove that his conjecture had been correct. It seemed to me that the mists in my

own mind were gradually clearing away, and I began to have a dim, vague

perception of the truth.

 

“All this seems strange to you,” continued Holmes, “because you failed at the

beginning of the inquiry to grasp the importance of the single real clue which

was presented to you. I had the good fortune to seize upon that, and everything

which has occurred since then has served to confirm my original supposition,

and, indeed, was the logical sequence of it. Hence things which have perplexed

you and made the case more obscure, have served to enlighten me and to

strengthen my conclusions.

 

It is a mistake to confound strangeness with mystery. The most commonplace crime

is often the most mysterious because it presents no new or special features from

which deductions may be drawn. This murder would have been infinitely more

difficult to unravel had the body of the victim been simply found lying in the