Erskine Childers 
The Riddle of the Sands [EPUB ebook] 

The Riddle of the Sands: A Record of Secret Service is a patriotic British 1903 novel by Erskine Childers.It is a novel that 'owes a lot to the wonderful adventure novels of writers like Rider Haggard, that were a staple of Victorian Britain’; perhaps more significantly, it was a spy novel that 'established a formula that included a mass of verifiable detail, which gave authenticity to the story – the same ploy that would be used so well by John Buchan, Ian Fleming, John le Carré and many others.’ Ken Follett called it 'the first modern thriller.’