Theresa de Cepeda y Ahumada is the daughter of a nobleman from Ávila who refuses to accept her role as a woman in a man's world: she doesn't want to limit herself to being a wife and mother. She feels there must be more to life than that.

She wants to write, read and learn.

In her search for that "something" she is missing, Theresa enters a cloister. However, she soon becomes disappointed: behind the secluded walls of the convent, she encounters the same materialism and frivolity she was fleeing from outside before becoming a nun. She decides to embark on a crusade of prayer and sacrifice that turn her first into a rebel and a crazy woman, then a leader and finally a saint.

This is a chronicle about a unique woman who lived in a difficult time. She was a good-looking, strong woman who fought against the world and ultimately succeeded in finding herself a place in history.