Four "Picture Brides", from New Orleans, arrive in the Brazilian jungle on a riverboat, brought there to marry workers at Lottagrasso, a remote mining site of the Standard Diamond Mines.Also on the boat with the four "mail-order" brides (Americans Mame Smith, Flo Lane, and Gwen from England and Lena from Europe) is Mary Lee, a frightened and innocent girl, who has come to see the mine`s brutal supervisor, Von Luden , about a job. Knowing von Luden`s inhuman reputation, Mame transfers the photo assigning her to Dave Hart, to Mary`s Identification card. Castro, the mail-runner, delivers a letter to von Luden informing him that Hart, his partner, is wanted in the United States on an embezzlement charge. Mame, in order to protect Mary, presents herself as a job applicant while Mary is introduced to Dave and his fellow supervisors (Pete, Joe and Bill) as a bride applicant. Dave rescues Mary from a lustful and brutish attack by von Luden.