Cover of the 1959 1st edition.
Biggles at World's End by W. E. Johns was first published in 1959 by Brockhampton. There have been three subsequent editions in the English language, with the most recent being the 1966 edition by Hampton Library. The events in the book take place in the late 1950s in South America.
Von Stalhein, Biggles' former rival has been rescued from a Russian prison colony and settled in London. He offers a tantalizing piece of intelligence. There is a cache of gold which a German warship had captured from a British merchantman during the First World War. Biggles is sent to collect it but to do so he needs to travel to the Tierra del Fuego, at the extreme southern end of South America, literally the world's end. Biggles, tired of using obsolete cast-off or borrowed aircraft, is offered a new amphibian for his Air Police inventory--the Gadfly.
Gadfly - the first appearance of this amphibian. There is a detailed description of it in chapter 2.