On the other hand, let the guilty man or woman be a resolute and intelligent person, capable of setting his (or her) wits fairly against the wits of the police--in other words, let the mystery really _be_ a mystery--and cite me a case if you can (a really difficult and perplexing case) in which the criminal has not escaped.

Mind! I don't charge the police with neglecting their work.

No doubt they do their best, and take the greatest pains in following the routine to which they have been trained.

It is their misfortune, not their fault, that there is no man of superior intelligence among them--I mean no man who is capable, in great emergencies, of placing himself above conventional methods, and following a new way of his own.

There have been such men in the police--men naturally endowed with that faculty of mental analysis which can decompose a mystery, resolve it into its component parts, and find the clue at the bottom, no matter how remote from ordinary observation it may be.