An 18-year-old Indio woman in rural Mexico, Maria Concepción, is married to Juan. who serves as a laborer on an archaeological site operated by an American scientist. Newly pregnant, she cooks for the men. A 15-year-old girl, Rosa, is a local beekeeper. When Maria Concepción discovers that she and Juan are having an affair, she determines to exterminate both her female rival and her own unborn child conceived by Juan.
