The betrayed betrayer
Raven can be seen as a betrayer of his common man. As the Gun for Sale, he accepts assassination jobs for pay, trading human life for money. Anne learns later why he's like that, but in any case, he symbolizes the ultimate pariah. He cannot be in community with anyone, and in this story, he is betrayed. He is left alone in that betrayal, because his decisions have excommunicated him from society. He is the easiest frame for Davis's crooked purposes. This allegory speaks to the experience that an outsider has of community.
Anne as the symbolic witness
Anne is the person who has most to gain by catching Raven. Her own husband heads the pursuit for Raven, so a successful hunt would mean safety for her family. But, in this story, she ends up siding with Raven after everything is said and done. This symbolic journey makes her character a witness for the social issues that pushed Raven to his lifestyle. Their primary scene together is when Raven tells her his side of the story, starting in his youth.
The train
The train symbolizes time, because they are all trapped together on a journey forward. There is a beginning and an ending to the train ride, and so the train becomes a symbol for the journey of life toward death. In fact the story does indeed end with death. The idea of trains for passage also underscores the idea of mobility and change, because the systemic issues of the plot have to do with social mobility, an idea that is plainly evident on a train because different train cars have different amenities.
The enemy of an enemy
There is an instance of what the old adage describes: 'An enemy of my enemy is my friend.' Davis isn't just a pain in Raven's neck. He betrays the detective's wife, making her into his victim and leaving her for dead. In light of this, Anne is ready to see things from a new point of view. Perhaps this can be seen as a symbol for feminism. Another way of reading the symbol is that a villain doesn't have loyalty. Raven doesn't have loyalty either, but he doesn't seek his own interests; he just works for a paycheck.
The universality of death
Instead of showing a justice-oriented resolution, the main cast of the novel dies together—the boss, Davis, and Raven, all dead. This symbolizes the universality of death. Although the dilemma of the novel seems to be social justice and political manipulation, the narrative ends in death regardless of which path the character takes. This makes death a transcendent symbol for itself. The death of the characters is an unnerving reminder of the fate that awaits everyone on the "train" of life.
