The Hound of the Baskervilles & The Valley of Fear

But we hold several threads in our hands, and the odds are that one or other of them guides us to the truth. We may waste time in following the wrong one, but sooner or later we must come upon the right.

The more outré and grotesque an incident is the more carefully it deserves to be examined, and the very point which appears to complicate a case is, when duly considered and scientifically handled, the one which is most likely to elucidate it.