Two scions of a noble family lived in Bohun Beacon. Rev. Wilfred Bohun was a devout curate of the local Anglican parish. Colonel Norman Bohun, his older brother, was a blasphemous profligate.
Bohun Beacon had a lofty Anglican church building with interesting architecture. At the foot of the church was a smithy cluttered with hammers and scraps of iron. Across from the church was “The Blue Boar,” the only inn in town.
One morning Norman was enjoying the alcoholic beverages that the inn provided. As Wilfred was about to enter the church, Norman deliberately made him angry by speaking of his impending visit to the blacksmith’s wife. The blacksmith had gone to the neighboring town of Greenford.
After inveighing against his brother, Wilfred entered the church. To his surprise, the blacksmith’s nephew was inside praying. Because he was severely retarded, people called him Mad Joe. He usually did not come to church.
When Mad Joe left, Wilfred noticed that Norman was teasing the poor fellow.
While Wilfred was praying in the gallery, the church had another unusual visitor, namely, Gibbs, the cobbler, who was an atheist. He informed Wilfred that his brother had been killed.
When Wilfred and the cobbler arrived at the scene of the crime, the doctor was examining the body, and the inspector was investigating the murder. On a nearby bench, the wife of the blacksmith was shedding a copious supply of tears. She was a Roman Catholic, and her priest was talking to her. The Presbyterian minister was also present.
Norman had been wearing a round green hat, the inside of which was lined with steel. The hat was crushed and Norman’s skull was shattered. Someone had apparently struck Norman on the head with unbelievably strong force. A small hammer was lying nearby. Since it had blood on it, it was obviously the murder weapon.
The cobbler suspected Simeon Barnes, the blacksmith. He was the only man who could possibly deliver such a mighty blow. Moreover, he obviously had a motive.
The little Catholic priest was Father Brown. He picked up the hammer and looked at it. He objected that a powerful man like the blacksmith would not commit murder with a small hammer when there were so many larger hammers lying around.
While the group was discussing these things, the blacksmith returned to Bohun Beacon, accompanied by two residents of Greenford. After advising Barnes that he had the right to remain silent, the inspector arrested him in the name of the king.
The blacksmith did not remain silent. He forcefully commented on the eternal fate of the murdered man. He then pointed out that he had an ironclad alibi. From the testimony of the two Greenford residents, it was evident that the blacksmith was innocent.
Father Brown was still looking at the hammer. He again commented on its small size. This led the doctor to think that the wife of the blacksmith might have done it. She would undoubtedly use a small hammer because she would not be able to lift the heavy ones.
Father Brown expressed partial agreement with what the doctor said, but he objected that it would be physically impossible for her to deliver a blow powerful enough to smash Norman’s skull. To reinforce his argument, he pointed out that Norman had been wearing an iron helmet, which had been scattered like broken glass.
The doctor had to admit that Father Brown had spoken the truth. However, he said that there were objections to every imaginable theory, since no man except an idiot would use a small hammer when big ones were available.
Wilfred then said that he thought that an idiot had done it. Since Wilfred was a priest, he said that he did not want his testimony to send anyone to the gallows. However, he felt that he could freely accuse Mad Joe, since the law would not hang an idiot. He pointed out that an idiot would be likely to grab any hammer at random, big or small. Moreover, frantic idiots sometimes had the strength of ten men.
He also told the group what he had seen earlier in the morning. Mad Joe was praying in church. He suggested that a lunatic would be likely to pray before committing murder. Wilfred also mentioned that Norman teased Mad Joe after he left the church.
Father Brown admitted that Wilfred’s theory was essentially unassailable. However, he told the curate that his theory was not the true one. The doctor heard this remark and concluded that Father Brown knew more than he was telling.
In the meantime, the inspector and the blacksmith were talking to one another. The blacksmith wondered whether the inspector still suspected him. He pointed out that in spite of his strength, he could not have hurled the hammer all the way from Greenford. His hammer could not sprout wings and fly half a mile over hedges and fields.
The blacksmith had a theory. He believed that God Himself had delivered the blow that killed Norman.
Father Brown expressed a desire to inspect Wilfred’s church. He expressed interest in the architecture. Wilfred led him up some stairs to a high entrance.
As Father Brown was following Wilfred, the doctor expressed his suspicion that Father Brown knew more about the case than he was telling. Father Brown gave him two hints.
First, the devastating force that smashed Norman’s skull was well known to physical science. Secondly, the blacksmith’s statement about his hammer sprouting wings and flying across the country was close to the truth.
While Wilfred and Father Brown reached an outdoor gallery high above the ground, Father Brown pointed out that it was dangerous to pray in high places. While praying in a valley, a suppliant would humbly look up toward heaven. In contrast, while looking down from lofty heights, a person would soon succumb to a spirit of pride.
Father Brown told Wilfred that he once knew a man who used to pray with others before the altar on the ground floor of the church. However, he grew fond of praying in high and lonely places. He was a good man, but while viewing the world from his lofty perch, he began to think that he was God and had the right to judge his fellow men. Moreover, he had a powerful force at his disposal, namely, the force of gravity. Because of this powerful force, it seemed to him that he was invested with divine power.
He saw an insolent man strutting below in a green hat. From the heights, he looked small, just like a poisonous insect. It occurred to him that if he dropped a hammer on this creature, it would be like a devastating blow from heaven.
Wilfred now knew that Father Brown not only knew that he had killed his brother but also understood how and why he had committed this crime. He tried to climb over the parapet and plunge to his death, but Father Brown stopped him.
“Not by that door,” he said gently. “That door leads to hell.”
Father Brown told Wilfred that he was not planning to tell anyone what he knew. Wilfred would have to decide what to do. Because Wilfred had not tried to pin the blame on the blacksmith or his wife when he undoubtedly was tempted to do so, Father Brown figured that Wilfred had not gone far wrong and would make the correct decision.
Wilfred left the church, approached the inspector, and confessed that he had killed his brother.
Protestants (like me) may feel uncomfortable with some of the offhand comments that Chesterton makes in this story, but the plot is excellent. It is one of my favorite Father Brown mysteries.
To those Protestants who hesitate to read these mysteries because of Chesterton’s Roman Catholic orientation, I would like to make the following observation. A story with a Roman Catholic point of view is far better philosophically than the humanistic bias that pervades the average movie and most modern literature.
To write this summary, I consulted an online version presented by Project Gutenberg.
Project Gutenberg: The Innocence of Father Brown