Josep Alvarez is a young man in the tiny grape-growing village of Santa Eulalia, in northern Spain, where his father grows black grapes that are turned into cheap vinegar. Joseph loves the agricultural life, but he is the second son, and his father's vineyard will be inherited by his brother Donat, the firstborn. Josep yearns for a job growing grapes and for an opportunity to marry Teresa Gallego. In Madrid, an assassination plot, conceived against the political leader of Spain by men of wealth and power, creates a storm of intrigue that sucks into its vortex a group of innocent young farm workers in Santa Eulalia.
