Rugged mining engineer Rian Mitchell (Stewart Granger) discovers a lost emerald mine in the highlands of Colombia, which had last been operated by the Spanish conquistadors. Rian is a man consumed by the quest for wealth. However, he has to contend with local bandits and a savage jaguar.
Taken to recuperate at the plantation home of local coffee grower Catherine Knowland (Grace Kelly) and her brother Donald (John Ericson), Rian manages to charm Catherine.
His partner, Vic Leonard (Paul Douglas), is preparing to leave Colombia on the next ship. Rian, anxious to get Vic’s assistance to mine the emeralds, tricks him into staying. Returning to the mine, Rian first gets Catherine’s cooperation and then resumes his romantic overtures.
However, his greed to get the emeralds at any cost soon creates trouble. He comes into conflict with the chief of the local bandits, who threatens Catherine at her home. He also takes Donald into the mining operation, despite Donald’s complete inexperience, solely in order to obtain the coffee plantation workers on for his mining needs. This, however, means that Catherine does not have enough workers available to pick the coffee when harvest time arrives. Rian’s mining operations also put the plantation at risk of flooding.
When a tragic accident at the mine site kills Donald, even Vic abandons his old friend Rian and sets out to help Catherine with her harvest, all the while harboring his own passion for the beautiful young woman.
It takes a final shootout between the bandits and Rian’s men, in which Catherine and Vic do support him, for Rian to finally come to his senses and realize his mistakes. At great risk to himself, he sets in place an explosion of dynamite that not only diverts the water away from Catherine’s plantation, but also buries the mine under tons of rubble, from where it can no longer be reached. Rian then reunites with a forgiving Catherine.