E.Phillips Oppenheim 
Ambrose Lavendale, Diplomat 

Ambrose Lavendale, Diplomat is an episodic World War I novel written by E. Phillips Oppenheim that was first published as a serial in 1916, before the United States had joined the conflict, and then as a book in 1920. The plot of the novel revolves around World War One, Mr. Ambrose Lavendale, a young English-American ambassador, quits the embassy to act as a secret agent in London. He runs into Mlle. The French employee Suzanne de Frayne is observing a scientist who has created the formula for a deadly gas bomb. The two discover German spies, thwart schemes to steal ammunition from the Allies, steal secret weaponry, and fall in love in a series of interconnected episodes. The protagonist of the next-to-last story experiences the repercussions of submarine warfare on American ships. To know the ending of this story readers should go through the book that will generate interest to read it!