There are seventy-five perfumes, which it is very
necessary that a criminal expert should be able to distinguish from each
other, and cases have more than once within my own experience depended
upon their prompt recognition. The scent suggested the presence of a
lady, and already my thoughts began to turn towards the Stapletons. Thus
I had made certain of the hound, and had guessed at the criminal before
ever we went to the west country.

"It was my game to watch Stapleton. It was evident, however, that I
could not do this if I were with you, since he would be keenly on his
guard. I deceived everybody, therefore, yourself included, and I came
down secretly when I was supposed to be in London. My hardships were
not so great as you imagined, though such trifling details must never
interfere with the investigation of a case. I stayed for the most
part at Coombe Tracey, and only used the hut upon the moor when it was
necessary to be near the scene of action. Cartwright had come down with
me, and in his disguise as a country boy he was of great assistance
to me. I was dependent upon him for food and clean linen. When I was
watching Stapleton, Cartwright was frequently watching you, so that I
was able to keep my hand upon all the strings.

"I have already told you that your reports reached me rapidly, being
forwarded instantly from Baker Street to Coombe Tracey. They were of
great service to me, and especially that one incidentally truthful piece
of biography of Stapleton's. I was able to establish the identity of
the man and the woman and knew at last exactly how I stood. The case
had been considerably complicated through the incident of the escaped
convict and the relations between him and the Barrymores. This also you
cleared up in a very effective way, though I had already come to the
same conclusions from my own observations.

"By the time that you discovered me upon the moor I had a complete
knowledge of the whole business, but I had not a case which could go to
a jury. Even Stapleton's attempt upon Sir Henry that night which ended
in the death of the unfortunate convict did not help us much in proving
murder against our man. There seemed to be no alternative but to
catch him red-handed, and to do so we had to use Sir Henry, alone and
apparently unprotected, as a bait. We did so, and at the cost of a
severe shock to our client we succeeded in completing our case and
driving Stapleton to his destruction. That Sir Henr