Some detectives can never see beyond the length of their noses. They seize upon the first clew offered and hold to it like grim death, never stopping to think that what they consider a clew may be only a bait.
Such men can never make their mark in this business, no matter how long they stick at it. They are constantly getting into hot water, and have only themselves to blame.
Now a word more about my young friend Doyle.
He is sharp, shrewd and persevering, but in spite of it he is only adapted to certain kinds of work, and can never hope to become a great success.
Why?
Simply because he is not possessed of all the qualifications I have laid down.
Dave lacks education. He has never in his life moved in good society. Often it becomes necessary for a detective to disguise himself as a high-toned gentleman and move in the best society of the land.
To send Dave Doyle on such a mission would be worse than nonsense. He would fail before he had the chance to begin.
Take a case where it is necessary to track a man through the slums and Dave hasn’t his equal. Take a case of shadowing where untiring vigilance and bulldog pertinacity are the principal requirements, and he is there, too, but in disguises he’s just nowhere. That freckled face and red hair of his is a dead give away—you understand what I mean.
To be a successful detective a man must be a thorough gentleman in every sense of the word.