Blanca por fuera y Rosa por dentro (1971)

Blanca and Ramiro are an unconventional marriage. They argue continuously for the mere pleasure of subsequent reconciliation. Blanca had a sister, Rosa, who died in a car accident a few years ago, leaving Héctor Villarreal a widower, a novelist of some renown who once fell in love with Blanca and was never able to overcome the loss of his wife. After one of her daily marital discussions, Blanca leaves with the maiden on the road to Algeciras and has an accident right in the same place where her sister had it years before. As a result of this accident, Monica, the maiden, goes from being an amnesic to possessing a gifted memory, while Blanca, in addition to being totally amnesic, suffers an "ambivalent psychic dystrophy" that mentally makes her late sister Rosa.