What happens when you rediscover the love of your youth? In principle, you would live a love story, but this chapter of your life can not be written because it is prevented by a religious order. This is the plot that tells 'Perdóname, Señor' that gives life to the nun Lucía Medina. The conviction of this believer will be in danger when she returns to her hometown, Barbate, to tie things that were left loose when she surrendered to religion. There she will stumble over the love of her youth, Bruno, a mafia boss who is in the process of redemption. The abandonment of Bruno will free his position, which could be occupied by Rafa, Lucia's nephew, a young man.