Gonzalo and Marian Inchauspe live a quiet life in their comfortable house in the Delta. The couple's only concern revolves around their daughter Jimena, who is 20 years old and lives part time with a married man who has not been able to separate from his wife. But this seemingly calm daily life is shattered by a phone call. It is Juan Larralde, an old islander who has been released on parole after fifteen years of psychiatric imprisonment for the death of his daughter Valentina.
Gonzalo goes out to meet Juan Larralde who has returned to live in his old house in a hidden stream of the delta, known as Isla Negra (Black Island). The urgency of his departure behind Marian's back has its reasons: Juan Larralde has kidnapped Jimena in his house and intends to settle old scores with Gonzalo, blaming him for Valentina's death when she was Jimena's nanny as a teenager. That old wound from the past reappears and nothing will ever be the same again when everything comes to light: not only Gonzalo and Valentina's romance, but also the forbidden love between Marian and the young baby sister that was kept hidden all these years.