Luísa is a romantic, dreamy and delicate young woman married to Jorge, an engineer, a man of good habits and good economic conditions. They didn't know each other well, but got married and Luísa was a good wife, "she was clean and happy as a bird". Everything get changed when she meets a childhood love, her cousin Basílio. What seemed to be a great adventure will became a nightmare and Luísa will discover the price of her infidelity.