Summer. Muggy weather. Exam days. Miguel, a studious young man of normal habits, has brilliantly finished his degree in Law and is congratulated. His colleagues have had different luck. One student, frivolous girl, suspended/failed, has organized, nevertheless, a party at her country house on the outskirts of Madrid. The party, of modern tone, bewilders/stuns the friends, disturbs/upsets even the most formal. Miguel, who has come to it with his fiancée Cristina, and Manolo with his girlfriend Luz, have as much fun as other young people of less scrupulous behavior; so that, upon returning to the capital, paired off, both couples succumb to temptation, the irreparable happening. Then the boys appear sincerely sorry and fearful of the consequences.