Edgar Wallace 
The Joker [EPUB ebook] 

Mr. Stratford Harlow, the colossus of British Finance, was a gentleman with no particular call to hurry. By every standard he was a member of the leisured classes, and to his opportunities for lingering, he added the desire of one who was pertinently curious. The most commonplace phenomena interested Mr. Harlow. He had all the requisite qualities of an observer; his enjoyment was without the handicap of sentimentality, a weakness which is fatal to accurate judgement. Between Stratford Harlow and James Carlton, whom Harlow described as Scotland Yard’s most unscrupulous man, there was never open warfare until the murder of Mrs. Gibbons…