The new American consul to Singapore asks trapper Frank Buck to search the interior for a missing American agent carrying the Japanese plans for an invasion of the Malay Peninsula.

Frank competes with an old friend and rival to see who can capture a black leopard for an important client, while Gloria tries to recover the stolen jewelry of an important American woman.

Frank and a lady photographer are captured by a fierce tribe ruled by an escaped convict, who gives them one chance to outrun the tribe's hunters.