British Intelligence agent Leo Marzell (Leo Carrillo) persuades scientist-explorer David Lynd (Don Terry) to postpone his wedding to wealthy sportswoman Jane Claymore (Louise Allbritton) to undertake an expedition to a south Pacific island, along with his photographer pal Andy Parker (Andy Devine). They face all manners of danger , from pythons to head-hunter attacks, as they set out to find the arsenal that Axis agent Tagani (Turhan Bey) has hidden in the hills for use when world-war-two breaks out in the Pacific and Asia.