Walter (Miguel Óscar Menassa) is married to Silvia (Cruz Gonzalez), but realizes that the desire his wife feels for other men leads her to sleep with his friend Gustavo (Luis Miguel Seguí). She decides to confess to her husband the whole truth in front of her lover, but infidelity is not always committed in the same way. A writer who cheats her husband and is cheated at the same time and a mature woman with much to live, are other infidels. Through their comic and emotional stories, a whole treatise on infidelity is elaborated.

A new doctor arrives in a small Spanish village. As soon as he begins meeting people there, he notices the strange behaviour of the population and is surprised. Young people make fun of him, a man called Gonzalo seems to be some kind of leader, and he is invited to leave the village when he tries to ask about the situation. All his questions get no answer. His neighbour is a lovely and pretty young woman, who works as the local teacher. They develop a sincere friendship from the very first moment, which grows to become love. Unfortunately, Gonzalo feels that the young teacher is "reserved" exclusively for him and he reacts with violence. Meanwhile, the doctor finds out the key of that strange behaviour. Some years ago, during the local feast, some drug-addicts attacked the village in order to get money and goods. There was a fight and some people died, including Gonzalo's son. From then on, Gonzalo and others began their particular "crusade" against drug-addicts.