Erskine Childers 
The Riddle of the Sands [EPUB ebook] 

The Riddle of the Sands: A Record of Secret Service 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.
Robert Erskine Childers   (25 June 1870 – 24 November 1922), was an English-born Irish nationalist who established himself as a writer with accounts of the Second Boer War, the novel
The Riddle of the Sands about German preparations for a sea-borne invasion of England, and proposals for achieving Irish independence.