William Le Queux 
Gamblers 

A crime novel set in the south of France where a gambler wins plenty of money only to have it removed from him with fatal consequences. The narrator of the novel, Carmela Rosselli, was friendly with the gambler and when he is discovered in her room she sets about trying to discover who caused him harm. Her quest takes her all over the fashionable south of France, on a cruise around the Mediterranean and finally to Paris. There are plenty of shady characters around on whom suspicion falls and Carmela is confused as to who is who and what is what. But, in the tradition of all good crime novels, she eventually works out what has gone on and, in a somewhat surprising finale, solves the mystery. The feel of early 20th century France is admirably captured in a novel, typical of the period, redolent with plenty of melodrama. (Goodreads)