Susana is a fallen girl. At the beginning we see her in a reformatory, but the reasons that brought her there remain in the dark. We just find out that she has learned nothing new in the two years she has spent there and that she behaves in the same unruly and rebellious way like when she was first admitted to the place.
She is brought into a dark and sinister cave which is teeming with rats and spiders. We know nothing about the reasons for this punishment and we can't avoid feeling sorry for her: Whatever she might have done, it does not justify an inhuman treatment such as this.
Susana is religious, and the god she calls on is kind and generous. So the miracle happens, the bars of the prison cell at which she is rattling suddenly give way and she succeeds in escaping into a night full of darkness and relentless rain.
She even can make it into paradise: A landowner's family takes her in, after she has told them a pack of lies. She is allowed to work as a maid and gains the confidence and the affection of the mother, while the father at first has a disapproving attitude towards her.
But the family's son and the steward live on the estate, too, and they don't fail to notice Susana's outstanding physical attraction. As the girl also knows how to place her charms, they both fall victim to her.
Susana, however, does not seem capable of developing any true feelings. Life is just a villainous game for her in which the rules are set by herself. The aim is to destroy the well established order. When finally even the landowner succumbs to the lure of love the initial situation becomes reversed and nothing stays the same: the mother turns into an enraged enemy, while father and son become rivals and the steward is dismissed.
It is then the latter who sets the decisive ball rolling which leads once more to a reversal of the circumstances: He finally makes use of his knowledge of Susana's escape from the reformatory, which up to now he kept to himself in order to increase his chances of winning Susana's favor, and Susana, however fiercely she may be defending herself, cannot avoid being arrested.
The game is lost, and, as it often happens in a melodrama, it is the refused lover, who makes it break down. In the end, the episode with Susana means nothing more than the memory of a nightmare for the landowner's family. And, after the re-establishment of the initial situation, the characters cannot help asking themselves if everything has really happened.
The attentive spectator will come to a different conclusion. He will notice the fundamental fragility of an order that is well established only in appearance. And he will not be able to avoid drawing a frightful parallel to his own life, in which nothing is secure and reliable either.