The Secret of the Fox Hunter — William Le Queux

Along with E. Phillips Oppenheim, William Tufnell Le Queux was one of the earliest practitioners of the modern espionage novel, creating the character of the 'rogue male' lone-wolf secret agent that would go on to be central to the work of authors such as Geoffrey Household, John Buchan, Eric Ambler and Ian Fleming.

Excerpt

I was much gratified that I had concluded a very difficult piece of espionage, and having obtained the information I sought, had been able to place certain facts before my Chief, the Marquess of Macclesfield, which had very materially strengthened his hands in some very delicate diplomatic negotiations with Germany. Perhaps the most exacting position in the whole of British diplomacy is the post of Ambassador at Berlin, for the Germans are at once our foes, as well as our friends, and are at this moment only too ready to pick a quarrel with us from motives of jealousy which may have serious results.