The perennial classic. Arguably the first spy novel ever written that remains one of the finest examples of the genre to this day.Carruthers, a Foreign Office clerk with a taste for yachting, joins his former schoolmate, Davies, for a spot of sailing on the North Sea. Carruthers is initially disdainful of their rather rudimentary vessel, the Dulcibella; but he warms to the voyage when they detect suspicious German naval activity off the coast of the Frisian Islands. Pretending to be hunting duck, the friends decide to investigate the Germans' intentions - self-appointed secret agents. In no time they become embroiled in a world of suspense and intrigue, and the pair set about foiling a plot to invade England.