Doña Pura, don Benito and don Augusto are three venerable old people who usually coincide each month in the queues of the mutuality windows to collect their pension, an opportunity they take advantage of to talk about life. When they learn that the old don Felipe, an acquaintance, is very sick and is alone and without money for a decent funeral, they decide to ask for a loan to help him, but, as they do not grant it, they decide to rob the savings bank. To do this, they will plan everything thoroughly and manufacture a homemade explosive.
San Ginés de la Sierra is a small village lost in the mountains in southern Spain. It is known throughout the region for two peculiar characteristics: its "persistent" drought and a "Home of the Vanquished". This "home" is an institution that houses some twenty old people, to whose care are eleven nuns and crosses a distressing economic situation. The nuns are desperately seeking a solution and decide to hold a charity bulls run.
Viridiana is preparing to start her life as a nun when she is sent, somewhat unwillingly, to visit her aging uncle, Don Jaime. He supports her; but the two have met only once. Jaime thinks Viridiana resembles his dead wife. Viridiana has secretly despised this man all her life and finds her worst fears proven when Jaime grows determined to seduce his pure niece. Viridiana becomes undone as her uncle upends the plans she had made to join the convent.