Madame Defarge’s accidental death is an example of situational irony. At the beginning of the novel, Madame Defarge believes that she is an agent of fate. Speaking to her husband about the revolution, she says, “although it is a long time on the road, it is on the road and coming […] Nothing that we do is done in vain."
However, the actual circumstances of Madame Defarge’s death contrast her belief that nothing is in vain. Near the end of the novel, she mistakenly shoots herself during an altercation with Lucie’s servant, Miss Pross. In a letter to writer John Forster, Dickens explained that an accidental death was the only fitting punishment for Madame Defarge, since she would have been happy to die in the street, fighting for her cause.
Jerry Cruncher spends so many years doing odd jobs for Tellson’s Bank that he becomes a de facto employee of the respectable institution. However, the scrupulous Mr. Lorry of Tellson’s spends almost the entirety of the novel unaware of Cruncher’s secret moonlight occupation as a “resurrection man,” or in other words, a graverobber.
Though the audience learns of Cruncher’s illegal activities early on, Mr. Lorry remains in the dark until Chapter Eight, Book Three, when, in order to unmask the spy Barsad, Cruncher must reveal how he knew that Roger Cly’s coffin was empty. Only then does Mr. Lorry discover that the self-appointed “honest tradesman” is not so honest. The disconnect between what Mr. Lorry knows and what readers know is an example of dramatic irony.
Dickens uses verbal irony when he describes the prominent place that the guillotine holds in the people’s imagination:
It was the sign of regeneration of the human race. It superseded the Cross. Models of it were worn on breasts from which the Cross was discarded, and it was bowed down to and believed in where the Cross was denied.
Referring to a machine that was invented for mass killing as a “sign of regeneration” is certainly ironic. However, the phrase also contains a kernel of truth, since one of the characteristics of Monseigneur, the synecdochic figure for the aristocracy, is his devastation of the land. By killing off Monseigneur, the revolutionaries hope to usher in a new era of fertility.
Manette’s unintentional condemnation of Darnay is an example of situational irony. The words Manette wrote about Darnay’s ancestors while he was in prison are read to the court:
I believe that the mark of the red cross is fatal to them, and that they have no part in His mercies. And them and their descendants, to the last of their race, I Alexander Manette, unhappy prisoner, do this last night of the year 1767, in my unbearable agony, denounce to the times when all these things shall be answered for. I denounce them to Heaven and to earth.
Despite Manette’s endeavors to use his influence as a former prisoner of the Bastille to free his son-in-law, it is Manette’s own letter, coming back to haunt him, that sentences Darnay to the guillotine. Manette would never consciously desire Darnay’s downfall. However, the fact that he is listed among Darnay’s accusers highlights the underlying rivalry for Lucie’s love that exists between Manette and Darnay.
Darnay’s ignorance of Carton’s plan to sacrifice himself in Darnay’s place is an instance of dramatic irony. In the prison cell, when Carton asks Darnay to switch clothes with him, the unsuspecting Darnay is as compliant as “a young child in his hands.” Though Darnay writes his wife a long parting letter explaining why he kept his noble birth a secret, Carton forces him to write a new letter, the substance of which Darnay does not understand. The letter contains Carton’s last words to Lucie, and it reads:
If you remember […] the words that passed between us, long ago, you will readily comprehend this when you see it. You do remember them, I know. It is not in your nature to forget them.
Carton’s letter references his long-ago declaration of love to Lucie, an event which Darnay likely knows nothing about. Shockingly enough, Darnay obeys Carton’s unorthodox parting requests without suspecting Carton’s true intention—to die in his stead. Readers, who are familiar with Carton’s earlier promise to sacrifice himself for Lucie, understand the letter’s meaning, though Darnay does not. Darnay’s ignorance casts him in a surprisingly passive role for a romantic hero and imbues the scene with a sense of dramatic irony.