Sherlock Holmes sat for some time in silence, with his head sunk forward and

his eyes bent upon the red glow of the fire. Then he lit his pipe, and leaning

back in his chair he watched the blue smoke-rings as they chased each other up

to the ceiling.


“I think, Watson,” he remarked at last, “that of all our

cases we have had none more fantastic than this.”


“Save, perhaps, the Sign of Four.”


“Well, yes. Save, perhaps, that. And yet this John Openshaw seems to me

to be walking amid even greater perils than did the Sholtos.”


“But have you,” I asked, “formed any definite conception as

to what these perils are?”


“There can be no question as to their nature,” he answered.


“Then what are they? Who is this K. K. K., and why does he pursue this

unhappy family?”


Sherlock Holmes closed his eyes and placed his elbows upon the arms of his

chair, with his finger-tips together. “The ideal reasoner,” he

remarked, “would, when he had once been shown a single fact in all its

bearings, deduce from it not only all the chain of events which led up to it

but also all the results which would follow from it. As Cuvier could correctly

describe a whole animal by the contemplation of a single bone, so the observer

who has thoroughly understood one link in a series of incidents should be able

to accurately state all the other ones, both before and after. We have not yet

grasped the results which the reason alone can attain to. Problems may be

solved in the study which have baffled all those who have sought a solution by

the aid of their senses. To carry the art, however, to its highest pitch, it is

necessary that the reasoner should be able to utilise all the facts which have

come to his knowledge; and this in itself implies, as you will readily see, a

possession of all knowledge, which, even in these days of free education and

encyclopædias, is a somewhat rare accomplishment. It is not so impossible,