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.