William Le Queux 
Red Widow; or, The Death-Dealers of London [EPUB ebook] 

Excerpt: ""I can’t understand what it all means. The whole thing is a mystery-a great mystery! I have my suspicions-grave suspicions!" declared the pretty blue-eyed girl emphatically. "Of what?" asked the young man strolling at her side along the sunny towing-path beside the Thames between Kew and Richmond. "Well-I hardly know, " was her hesitating response. "But I don’t like auntie to remain in that house any longer, Gerald. Some evil lurks there; I’m sure of it!" Her companion smiled. "Are you quite sure you are not mistaken, Marigold?" he asked in a dubious tone. "Are you absolutely certain that you really saw Mr. Boyne on Thursday night?" "Why, haven’t I already told you exactly what I saw?" asserted the girl excitedly. "I’ve related in detail all I know. And I repeat that I don’t like auntie being there any longer." "Well, " said the young man, as they strolled leisurely along near the water’s edge on that Sunday afternoon in summer, their intention being to take tea at Richmond, "if what you have described is an actual fact, then I certainly do think we ought to watch the man very closely." "You don’t doubt me-do you?" exclaimed the girl, with quick resentment."