"The Riddle of the Sands" is a classic adventure novel written by Erskine Childers, a British author and politician. The novel was published in 1903 and is considered one of the earliest examples of the espionage thriller genre. Childers, who had a keen interest in sailing and maritime matters, drew upon his own experiences to create a gripping tale of intrigue and suspense. The story is set against the backdrop of rising tensions between Britain and Germany in the years leading up to World War I. The protagonists, Carruthers and Davies, embark on a sailing trip along the Frisian Islands and the German Bight. As they navigate the waters, they become embroiled in a mysterious plot involving German plans for an invasion of England. The novel is known for its attention to detail regarding sailing and navigation, and it incorporates elements of espionage, intrigue, and the geopolitical climate of the time.