Historical document or incredible adventure ??

Unable to put this book once begin, the author leads us through a delirious history, so inventive that one wonders how it could not be true! The hero, Paul Delroze fighting the Germans in Time of War (1914-18), and at the same time, the horrible perpetrator of a crime in his past. Gradually, as we advance in the adventure with him, everyone entremelle. Having been extremely well studied historically, I now wonder what parts of the book are true and what fictitious parties. Read it and you deduct same.