Steve Sinclair is a world-weary former gunslinger, now living as a peaceful farmer. Things go wrong when his wild younger brother Tony arrives on the scene with his new bride Joan Blake.
In Colombia, mining engineer Rian Mitchell discovers Carrero, the lost emerald mine of the Conquistadors, but has to contend with notorious local bandit El Moro's gang and with coffee planter Catherine Knowland's love.
David Marshall Williams is sent to a prison farm where he works in the tool shop and eventually develops the precursor of the famous M-1 Carbine automatic rifle used in World War II.
