"The Hint of an Explanation" by Graham Greene is full of symbols. The story takes place on a train, and two strangers, on an agnostic and the other a Catholic, share a compartment for the journey. After a time, the men begin to talk, and soon the Catholic tells a story which, we discover, is the story of his journey to true faith. The train on which they are riding is a metaphor for the journey he has traveled to get where he is today.
The story centers around a baker named Blacker. Blacker is physically ugly, and his hatred of Catholics makes him even more awful. Without saying it directly, the storyteller says he believes this man was an emissary of Satan's demons, though he tries never to speak the name of Satan.
"I sometimes think that Blacker was 'the servant of the servants of . . .[Satan].'"
Blacker is an embodiment (symbol) of the devil in this story. He constructs an "elaborate seduction" to entice the young David (the storyteller) into a grand sin. He wants the boy to steal a consecrated Communion wafer from the Church, and he systematically entices the boy with a train set. "How skilfully and unemphatically he...sowed the longing" for this train in this young Catholic boy. He starts by luring the boy in to play with the train set; soon the boy comes every day, and eventually he longs beyond measure for the train.
The train set is also a symbol in this story. It represents sin, the thing (or things) which begin as a harmless or intriguing interest but end up entrapping us. David's interest in the train began harmlessly enough, but soon he is consumed by the thought of the train and then wants to possess it completely. He is trapped into doing whatever he must in order to have it. Satan uses such harmless things in our lives to entice us away from truth or into trouble.
The most obvious symbol in the story is the holy bread, the wafers which are kept in boxes at the church but are transsubstantiated (literally transformed) into the body of Christ once they are consecrated. Blacker is a baker of breads, and he tries to replicate the wafers. The shape is not quite right, and David reminds Blacker that his wafers have not been consecrated. This evil man trying to usurp the role of God is clearly a symbol for Satan, the great usurper.
David reluctantly agrees to steal a consecrated wafer for the man, but he recognizes that he cannot take this small bit of bread lightly. That night David is restless as he ponders the "little damp mess of pulp" he has placed on a chair by his bed. He finally answers the whistle outside his window. It is the overeager Blacker, who has come to collect his prize--not the bread but the boy. In the end, though, David cannot do it, and he swallows the bread. He is saved. Blacker begins to weep and walks away dejectedly. The grown-up David says,
"[I]t's almost as if I had seen that Thing [representative of Satan] weeping for its inevitable defeat. It had tried to use me as a weapon, and now I had broken in its hands and it wept its hopeless tears....
If David had given Blacker the bread, he would have lost his soul, or at least his faith, to Satan.
Through his encounter with Blacker, David realizes that something he had memorized in his catechism classes and practiced lifelessly in Mass is real; now the fact that Jesus gave His body for the remission of our sins is truth to him. In fact, it became so real to him that he became a Catholic priest, something which has made him "a very happy man."