During the 1950s, in a small isolated Mexican village, the local Roman Catholic priest, Father Gomez (Leslie French), is an older man with a broken spirit. During his tenure in the village of Quantano, he fought hard to keep his flock of parishioners, in spite of threats and intimidation from the part of local bandit Anacleto Comachi (Sir Dirk Bogarde) and his men. The atheistic bandit has imposed his tyrannical rule over the region for many years. The local Police cannot find any witnesses to come forward and testify to any wrongdoing from the part of Anacleto. Therefore, they cannot charge him or arrest him. The Catholic Church replaces Father Gomez with a younger, more energetic priest, Father Keogh (Sir John Mills) from Ireland. Before departing the village, Father Gomez warns Father Keogh of the dangers of defying Anacleto Comachi's authority. But Father Keogh openly defies the bandit and administers his daily priestly duties at the village church. He even manages to persuade some of the villagers to start attending church again. In retaliation, Anacleto tries to intimidate the priest by starting to murder the villagers in alphabetical order. He also plans a few attempts on the priest's life. Coming between them, Locha (Mylène Demongeot), the beautiful daughter of the major local landowner, brings a bit of reason, sanity, and innocence to this violent world. Anacleto promises to Father Keogh to mend his ways and embrace religion if Father Keogh can persuade him that it's the religious message and teachings, not the personality and charisma of the priest that drives the faith. Father Keogh accepts the challenge and invites Anacleto to live with him and read the Bible. Upon doing this, Anacleto discovers Father Keogh's little secret.