The Riddle of the Sands is a 1903 novel by Erskine Childers. The book, which enjoyed immense popularity in the years before World War I, is an early example of the espionage novel and was extremely influential in the genre of spy fiction. It has been made into feature-length films for both cinema and television. The novel "owes a lot to the wonderful adventure novels of writers like Rider Haggard, that were a staple of Victorian Britain". It was a...