To prevent David's widowed mother, Elizabeth, from being influenced by her son against their fake tropical rubber plantation investment, the promoters trick David into managing the plantation in Mexico. Seeking to prove his worth after a failed marriage proposal, David travels to the tropics. There, he encounters the brutal reality of the rubber slavery system. He meets Ludwig Hertzer (the villainous "Planter," played by Tyrone Power Sr.), a feared and hated man who runs a slave-labor-based operation. David also encounters Senora Morales and her daughter, Consuela, who are involved in the slave trade. David discovers his family's investment is actually a "rubbish heap." He attempts to warn his mother via cable, but the message is intercepted by Hertzer for his own gain.

Tyrone Power Sr.
Ludwig Hertzer

Harry Davenport
Short

Lamar Johnstone
David Mann

Pat Hartigan
Andy Meagher

Lottie Kruse
Kate Sommers

Carmen Phillips
Mrs. Tyrone Power
Consuela
Lucille King
Andrea
Mabel Wiles
Patricia
Pearl Elmore
Señora Morales
Lalo Encinas
Magdaleno
George Benjamin O'Dell
Yaqui Chief
Alice Winchester
Yaqui Chief's Sister
James Donald
Yaqui Father
Louis Fitzroy
George Ewing