In a small convent immersed in the tranquility of the Tuscan countryside, four friars spend their days: Raniero, the gruff but friendly guardian, Gervasio, jovial but hypochondriac, the naive Bettino, and Vittorio, an elderly friar who tends the garden. Their daily routine is disrupted by the arrival of Antonio, who quickly wins the trust of the three friars, but not that of Raniero, who views him with great suspicion. The two engage in acts of espionage in an attempt to discover something about each other's past. While rummaging through Antonio's cell, Raniero makes a shocking discovery about an unspeakable secret...