A few important symbols in A Tale of Two Cities include the recurring image of footsteps, the wine cask breaking and shadows.
Throughout the novel, footsteps in the distance are a motif that foreshadows the impending doom in France. The revolution is coming and even in London, the distance of the footsteps can be heard in the front room of Lucie & Darnay's apartment. The footsteps symbolize the vengeance of the revolutionaries. The last chapter is titled "The Footsteps Die Out Forever" indicating that the revolution and danger is over. Lucie & Darnay are happy with little Lucie and their son little Sydney.
Shadows are often linked with Madame Defarge. She can "cast a shadow" over Lucie, and the chapter in which they explain her family and past is called "The Substance of the Shadow" indicating that Mme. Defarge is the shadow. Her connection with darkness indicates her evil nature, but this chapter conveys that she is also someone to be pitied. She is not a flat character (like a shadow is without depth) but rather there are reasons for her evil nature. The shadow and dark imagery throughout the novel therefore represents evil.
The wine cask breaking at the beginning of the novel leaks wine all over the cobblestone. The peasants run to the cask scooping up the wine, celebrating together in the streets. One man uses the wine from the street to paint the word blood on the walls in an alley. This obviously foreshadows the wine spilling in this scene to the wine spilling in the revolution. Like in previous scenes, Dickens uses animal diction to characterize the peasants who are "tigers" violently lapping up as much wine as they can. The imagery in this chapter illustrates the energy, violence and desperation of these peasants. It thematically connects to the idea of mob mentality as being both treacherous and dangerous.