Two Englishmen, while cruising in the Baltic, discover German preparations for an invasion of England. Written in 1902, this suspenseful tale is widely recognized as the first modern spy thriller.

The First Modern Spy Thriller: The Riddle of the Sands Two sail-boaters are cruising off the coast of Germany on a vacation. To their amazement they discover a German military exercise—a trial-run for the invasion of England. From ...