Biggles' team battle the stormy Southern Atlantic and a Russian group before finding buried treasure and two missing scientists.

goodreads summary

Biggles goes to the Southern most tip of South America in search of gold after a tip off from Erich von Stalhein. British gold has been hidden on an unknown island by the German Navy during the Second World War. Partly as a cover story, Biggles is additionally in search of two missing botanists called Carter and Barlow.