Study in Scarlet' and of 'The Sign of Four,' we have been
compelled to reason backward from effects to causes. I have
written to Lestrade asking him to supply us with the details
which are now wanting, and which he will only get after he had
secured his man. That he may be safely trusted to do, for
although he is absolutely devoid of reason, he is as tenacious as
a bulldog when he once understands what he has to do, and indeed,
it is just this tenacity which has brought him to the top at
Scotland Yard."

"Your case is not complete, then?" I asked.

"It is fairly complete in essentials. We know who the author of
the revolting business is, although one of the victims still
escapes us. Of course, you have formed your own conclusions."

"I presume that this Jim Browner, the steward of a Liverpool
boat, is the man whom you suspect?"

"Oh! it is more than a suspicion."

"And yet I cannot see anything save very vague indications."

"On the contrary, to my mind nothing could be more clear. Let me
run over the principal steps. We approached the case, you
remember, with an absolutely blank mind, which is always an
advantage. We had formed no theories. We were simply there to
observe and to draw inferences from our observations. What did
we see first? A very placid and respectable lady, who seemed
quite innocent of any secret, and a portrait which showed me that