"The Riddle of the Sands" by Erskine Childers is a pioneering spy novel set in the early 20th century. It follows two Englishmen, Carruthers and Davies, who uncover a German plot against Britain while sailing in the Frisian Islands. Combining adventure, espionage, and detailed nautical descriptions, Childers creates a tense and atmospheric tale of intrigue and patriotism.
