The Riddle of the Sands: A Record of Secret Service (Penguin Classics Series) by Erskine Childers, Erskine Childers (Introduction)

Loosely based on the author's own experiences, The Riddle of the Sands takes readers back to the early days of the twentieth century, when Britain shared a tense rivalry with the Kaiser's Germany. Tempted by the idea of duck shooting, Carruthers is lured by his friend Davies into a yachting expedition in the Baltic, only to discover that the itinerary involves more than killing fowl. Soon they're on a wild journey of intrigue, meeting danger at every turn, and ultimately unraveling Germany's secret plans to invade England. Tautly written and full of unexpected twists, this is a timeless work of espionage fiction.