Classicly

The Pawns Count is a detective novel written by English novelist E. Phillips Oppenheim, whose major works are in thriller genre.

It is during World War I. A chemist, Sandy Graham, has discovered a new powerful explosive, but he let's it slip in a London restaurant that he has made the discovery. Graham is ready to join some friends for luncheon at the restaurant but chooses to clean up before joining them. He never comes out of the restroom. Several spies from different governments set out to find him and the formula. What was particularly interesting to me about this espionage novel is that it was written in 1918, but it could just as easily have been from today. (Summary by Tom Weiss)