Englishman J. B. Priestley was born in 1894 and was writing books long before WWII. His first novel was published in 1927. Most of his works were Mystery or Thriller. As with any good author his stories are not limited to his nation's audience.

I label this book as SF but it could also be a Mystery or Thriller. Dangerous fanatics are in a position to inflict great damage upon all of mankind. It is an interesting adventure with some obligatory romance. It has the feel of a pre-WWII novel. The author showed good forward thinking as the World had not yet seen "the Bomb" when this was published. ( )