Published in the same year as El accidente, La señorita Medina [Miss Medina] also revolves around a secret, but unlike it, this is one that the original possessor has taken with her to the grave. The novel opens in a manner reminiscent of the author's first narratives, El Sur and Bene, since a first-person narrator is talking directly to her dead sister, Nieves, and indeed, as one learns more about her in the course of the novel, this Nieves turns out to be another social misfit, like the father in El sur, quite alien to the rest of the family's and the community's idea of normality. Like him too, she ended her own life and the narrator, called Silvia and just sixteen herself at the time, has only memories from thirty years earlier at the start of the novel, with which to try to piece together why. In search of a better understanding of her sister and their shared past, she develops a friendship with the eponymous character, a former nun and teacher from the school both girls had attended, but with whom Nieves had formed a special bond of friendship. Later in the novel, Silvia will also re-establish contact with Julio, Nieves's boyfriend, and start a love affair with him herself. Gradually, Silvia's two relationships – with Srta Medina and Julio – begin to link together as the secret of the suicide motive is slowly revealed to be one of multiple sexual jealousy. Srta Medina, it transpires, is a lesbian who was in love with Nieves and, whether she admitted it to herself at the time or not, she was jealous of her pupil's relationship with Julio. Julio, on his side, was secretly having an affair with a man, Ginés, while simultaneously seeing Nieves and it is Srta Medina's revelation of this infidelity in flagrante delicto that drives the already emotionally fragile Nieves to despair and death.

Thus, a search to find out a single secret – why Nieves committed suicide – turns out to be just one piece in a complex mosaic of interlinked secrets, only a few of which have been mentioned in the brief plot summary just given The final twist is that the revelation of the secret thirty years on by Srta Medina to Julio and Silvia leads Julio to his own death in a car crash.