Nelet and Marieta, two foster siblings from different social classes, were raised together in the country during their childhood, united by milk kinship. Upon meeting years later in the city, the affective bond between the young man, now a factory worker, and the young woman, will come into conflict as a result of the class boundaries and differences that separate them. Docudrama loosely based on the short story "El femater", by Vicente Blasco Ibáñez.